diff --git a/OpenTween.Tests/Api/GraphQL/CreateTweetRequestTest.cs b/OpenTween.Tests/Api/GraphQL/CreateTweetRequestTest.cs
index 87d48597a..7994fee81 100644
--- a/OpenTween.Tests/Api/GraphQL/CreateTweetRequestTest.cs
+++ b/OpenTween.Tests/Api/GraphQL/CreateTweetRequestTest.cs
@@ -22,7 +22,6 @@
 using System.Threading.Tasks;
 using Moq;
 using OpenTween.Connection;
-using OpenTween.Models;
 using OpenTween.SocialProtocol.Twitter;
 using Xunit;
 
diff --git a/OpenTween.Tests/Api/GraphQL/TimelineTweetTest.cs b/OpenTween.Tests/Api/GraphQL/TimelineTweetTest.cs
index 2ac9f04d4..baff23f05 100644
--- a/OpenTween.Tests/Api/GraphQL/TimelineTweetTest.cs
+++ b/OpenTween.Tests/Api/GraphQL/TimelineTweetTest.cs
@@ -19,17 +19,14 @@
 // the Free Software Foundation, Inc., 51 Franklin Street - Fifth Floor,
 // Boston, MA 02110-1301, USA.
 
-using System;
 using System.Collections.Generic;
 using System.IO;
-using System.Linq;
 using System.Runtime.Serialization.Json;
-using System.Text;
 using System.Text.RegularExpressions;
-using System.Threading.Tasks;
 using System.Xml;
 using System.Xml.Linq;
 using OpenTween.Models;
+using OpenTween.SocialProtocol.Twitter;
 using Xunit;
 
 namespace OpenTween.Api.GraphQL
diff --git a/OpenTween.Tests/Api/TwitterApiTest.cs b/OpenTween.Tests/Api/TwitterApiTest.cs
index 21b9c931d..979bf6473 100644
--- a/OpenTween.Tests/Api/TwitterApiTest.cs
+++ b/OpenTween.Tests/Api/TwitterApiTest.cs
@@ -21,18 +21,14 @@
 
 using System;
 using System.Collections.Generic;
-using System.IO;
-using System.Linq;
 using System.Net;
 using System.Net.Http;
 using System.Reflection;
 using System.Runtime.InteropServices;
-using System.Text;
 using System.Threading.Tasks;
 using Moq;
 using OpenTween.Api.DataModel;
 using OpenTween.Connection;
-using OpenTween.Models;
 using OpenTween.SocialProtocol.Twitter;
 using Xunit;
 
diff --git a/OpenTween.Tests/Models/PostClassTest.cs b/OpenTween.Tests/Models/PostClassTest.cs
index 291b061fa..5d632542e 100644
--- a/OpenTween.Tests/Models/PostClassTest.cs
+++ b/OpenTween.Tests/Models/PostClassTest.cs
@@ -20,13 +20,8 @@
 // Boston, MA 02110-1301, USA.
 
 using System;
-using System.Collections.Generic;
-using System.Linq;
-using System.Reflection;
-using System.Text;
-using System.Threading.Tasks;
+using OpenTween.SocialProtocol.Twitter;
 using Xunit;
-using Xunit.Extensions;
 
 namespace OpenTween.Models
 {
diff --git a/OpenTween.Tests/Models/PostFilterRuleTest.cs b/OpenTween.Tests/Models/PostFilterRuleTest.cs
index a83b42210..13e017e52 100644
--- a/OpenTween.Tests/Models/PostFilterRuleTest.cs
+++ b/OpenTween.Tests/Models/PostFilterRuleTest.cs
@@ -20,11 +20,8 @@
 // Boston, MA 02110-1301, USA.
 
 using System;
-using System.Collections.Generic;
-using System.Linq;
-using System.Text;
+using OpenTween.SocialProtocol.Twitter;
 using Xunit;
-using Xunit.Extensions;
 
 namespace OpenTween.Models
 {
diff --git a/OpenTween.Tests/Models/QueryCursorTest.cs b/OpenTween.Tests/Models/QueryCursorTest.cs
index 679c2f055..f520089d2 100644
--- a/OpenTween.Tests/Models/QueryCursorTest.cs
+++ b/OpenTween.Tests/Models/QueryCursorTest.cs
@@ -20,6 +20,7 @@
 // Boston, MA 02110-1301, USA.
 
 using OpenTween.Api.GraphQL;
+using OpenTween.SocialProtocol.Twitter;
 using Xunit;
 
 namespace OpenTween.Models
diff --git a/OpenTween.Tests/Models/StatusTextHistoryTest.cs b/OpenTween.Tests/Models/StatusTextHistoryTest.cs
index 01e240088..934768395 100644
--- a/OpenTween.Tests/Models/StatusTextHistoryTest.cs
+++ b/OpenTween.Tests/Models/StatusTextHistoryTest.cs
@@ -19,6 +19,7 @@
 // the Free Software Foundation, Inc., 51 Franklin Street - Fifth Floor,
 // Boston, MA 02110-1301, USA.
 
+using OpenTween.SocialProtocol.Twitter;
 using Xunit;
 
 namespace OpenTween.Models
diff --git a/OpenTween.Tests/Models/TabInformationTest.cs b/OpenTween.Tests/Models/TabInformationTest.cs
index 6f3dc460d..729463928 100644
--- a/OpenTween.Tests/Models/TabInformationTest.cs
+++ b/OpenTween.Tests/Models/TabInformationTest.cs
@@ -23,11 +23,10 @@
 using System.Collections.Generic;
 using System.Linq;
 using System.Reflection;
-using System.Text;
 using System.Windows.Forms;
 using OpenTween.SocialProtocol;
+using OpenTween.SocialProtocol.Twitter;
 using Xunit;
-using Xunit.Extensions;
 
 namespace OpenTween.Models
 {
diff --git a/OpenTween.Tests/Models/TabModelTest.cs b/OpenTween.Tests/Models/TabModelTest.cs
index b7dc70fed..f37505bb2 100644
--- a/OpenTween.Tests/Models/TabModelTest.cs
+++ b/OpenTween.Tests/Models/TabModelTest.cs
@@ -20,13 +20,10 @@
 // Boston, MA 02110-1301, USA.
 
 using System;
-using System.Collections.Generic;
 using System.Linq;
-using System.Text;
-using System.Threading.Tasks;
 using System.Windows.Forms;
+using OpenTween.SocialProtocol.Twitter;
 using Xunit;
-using Xunit.Extensions;
 
 namespace OpenTween.Models
 {
diff --git a/OpenTween.Tests/MyCommonTest.cs b/OpenTween.Tests/MyCommonTest.cs
index 32bbf2c03..f83b2fb01 100644
--- a/OpenTween.Tests/MyCommonTest.cs
+++ b/OpenTween.Tests/MyCommonTest.cs
@@ -20,19 +20,14 @@
 // Boston, MA 02110-1301, USA.
 
 using System;
-using System.Collections.Generic;
-using System.IO;
-using System.Linq;
 using System.Reflection;
 using System.Runtime.InteropServices;
 using System.Runtime.Serialization;
 using System.Text;
 using System.Windows.Forms;
 using Moq;
-using OpenTween;
-using OpenTween.Models;
+using OpenTween.SocialProtocol.Twitter;
 using Xunit;
-using Xunit.Extensions;
 
 namespace OpenTween
 {
diff --git a/OpenTween.Tests/SocialProtocol/Misskey/MisskeyPostFactoryTest.cs b/OpenTween.Tests/SocialProtocol/Misskey/MisskeyPostFactoryTest.cs
index 5d371ea6d..2d7c8d5b8 100644
--- a/OpenTween.Tests/SocialProtocol/Misskey/MisskeyPostFactoryTest.cs
+++ b/OpenTween.Tests/SocialProtocol/Misskey/MisskeyPostFactoryTest.cs
@@ -20,7 +20,7 @@
 // Boston, MA 02110-1301, USA.
 
 using OpenTween.Api.Misskey;
-using OpenTween.Models;
+using OpenTween.SocialProtocol.Twitter;
 using Xunit;
 
 namespace OpenTween.SocialProtocol.Misskey
diff --git a/OpenTween.Tests/Models/TwitterPostFactoryTest.cs b/OpenTween.Tests/SocialProtocol/Twitter/TwitterPostFactoryTest.cs
similarity index 99%
rename from OpenTween.Tests/Models/TwitterPostFactoryTest.cs
rename to OpenTween.Tests/SocialProtocol/Twitter/TwitterPostFactoryTest.cs
index 6ab4e5f21..510da86f0 100644
--- a/OpenTween.Tests/Models/TwitterPostFactoryTest.cs
+++ b/OpenTween.Tests/SocialProtocol/Twitter/TwitterPostFactoryTest.cs
@@ -22,6 +22,7 @@
 using System;
 using System.Collections.Generic;
 using OpenTween.Api.DataModel;
+using OpenTween.SocialProtocol.Twitter;
 using Xunit;
 
 namespace OpenTween.Models
diff --git a/OpenTween.Tests/TimelineListViewCacheTest.cs b/OpenTween.Tests/TimelineListViewCacheTest.cs
index 667e05f83..faabd971f 100644
--- a/OpenTween.Tests/TimelineListViewCacheTest.cs
+++ b/OpenTween.Tests/TimelineListViewCacheTest.cs
@@ -22,6 +22,7 @@
 using System;
 using OpenTween.Models;
 using OpenTween.OpenTweenCustomControl;
+using OpenTween.SocialProtocol.Twitter;
 using Xunit;
 
 namespace OpenTween
diff --git a/OpenTween.Tests/TimelineListViewStateTest.cs b/OpenTween.Tests/TimelineListViewStateTest.cs
index a49d74cbe..b6e8a6cdc 100644
--- a/OpenTween.Tests/TimelineListViewStateTest.cs
+++ b/OpenTween.Tests/TimelineListViewStateTest.cs
@@ -24,6 +24,7 @@
 using System.Windows.Forms;
 using OpenTween.Models;
 using OpenTween.OpenTweenCustomControl;
+using OpenTween.SocialProtocol.Twitter;
 using Xunit;
 
 namespace OpenTween
diff --git a/OpenTween.Tests/TweenMainTest.cs b/OpenTween.Tests/TweenMainTest.cs
index c51a29973..36bc985e2 100644
--- a/OpenTween.Tests/TweenMainTest.cs
+++ b/OpenTween.Tests/TweenMainTest.cs
@@ -20,9 +20,7 @@
 // Boston, MA 02110-1301, USA.
 
 using System;
-using System.Collections.Generic;
 using System.IO;
-using System.Linq;
 using System.Reflection;
 using System.Text;
 using System.Text.RegularExpressions;
@@ -33,9 +31,9 @@
 using OpenTween.OpenTweenCustomControl;
 using OpenTween.Setting;
 using OpenTween.SocialProtocol;
+using OpenTween.SocialProtocol.Twitter;
 using OpenTween.Thumbnail;
 using Xunit;
-using Xunit.Extensions;
 
 namespace OpenTween
 {
diff --git a/OpenTween.Tests/TweetDetailsViewTest.cs b/OpenTween.Tests/TweetDetailsViewTest.cs
index 928c35c6b..a03b11dd1 100644
--- a/OpenTween.Tests/TweetDetailsViewTest.cs
+++ b/OpenTween.Tests/TweetDetailsViewTest.cs
@@ -19,13 +19,9 @@
 // the Free Software Foundation, Inc., 51 Franklin Street - Fifth Floor,
 // Boston, MA 02110-1301, USA.
 
-using System;
-using System.Collections.Generic;
 using System.Globalization;
-using System.Linq;
-using System.Text;
-using System.Threading.Tasks;
 using OpenTween.Models;
+using OpenTween.SocialProtocol.Twitter;
 using Xunit;
 
 namespace OpenTween
diff --git a/OpenTween.Tests/TweetThumbnailTest.cs b/OpenTween.Tests/TweetThumbnailTest.cs
index 923a3e8b6..bdadda5d5 100644
--- a/OpenTween.Tests/TweetThumbnailTest.cs
+++ b/OpenTween.Tests/TweetThumbnailTest.cs
@@ -20,14 +20,12 @@
 // Boston, MA 02110-1301, USA.
 
 using System;
-using System.Collections.Generic;
-using System.Linq;
 using System.Net.Http;
-using System.Text;
 using System.Threading;
 using System.Threading.Tasks;
 using Moq;
 using OpenTween.Models;
+using OpenTween.SocialProtocol.Twitter;
 using OpenTween.Thumbnail;
 using OpenTween.Thumbnail.Services;
 using Xunit;
diff --git a/OpenTween/Api/DataModel/TwitterPageable.cs b/OpenTween/Api/DataModel/TwitterPageable.cs
index 5a5b01e45..fce5a0298 100644
--- a/OpenTween/Api/DataModel/TwitterPageable.cs
+++ b/OpenTween/Api/DataModel/TwitterPageable.cs
@@ -27,7 +27,7 @@
 using System.Runtime.Serialization;
 using System.Text;
 using System.Threading.Tasks;
-using OpenTween.Models;
+using OpenTween.SocialProtocol.Twitter;
 
 namespace OpenTween.Api.DataModel
 {
diff --git a/OpenTween/Api/GraphQL/CreateRetweetRequest.cs b/OpenTween/Api/GraphQL/CreateRetweetRequest.cs
index 16df55b24..0d5834606 100644
--- a/OpenTween/Api/GraphQL/CreateRetweetRequest.cs
+++ b/OpenTween/Api/GraphQL/CreateRetweetRequest.cs
@@ -25,7 +25,7 @@
 using System.Threading.Tasks;
 using System.Xml.XPath;
 using OpenTween.Connection;
-using OpenTween.Models;
+using OpenTween.SocialProtocol.Twitter;
 
 namespace OpenTween.Api.GraphQL
 {
diff --git a/OpenTween/Api/GraphQL/CreateTweetRequest.cs b/OpenTween/Api/GraphQL/CreateTweetRequest.cs
index d91da2527..e32394408 100644
--- a/OpenTween/Api/GraphQL/CreateTweetRequest.cs
+++ b/OpenTween/Api/GraphQL/CreateTweetRequest.cs
@@ -29,7 +29,6 @@
 using System.Xml.XPath;
 using OpenTween.Api.DataModel;
 using OpenTween.Connection;
-using OpenTween.Models;
 using OpenTween.SocialProtocol.Twitter;
 
 namespace OpenTween.Api.GraphQL
diff --git a/OpenTween/Api/GraphQL/DeleteRetweetRequest.cs b/OpenTween/Api/GraphQL/DeleteRetweetRequest.cs
index 500ed372e..5f06dc285 100644
--- a/OpenTween/Api/GraphQL/DeleteRetweetRequest.cs
+++ b/OpenTween/Api/GraphQL/DeleteRetweetRequest.cs
@@ -24,7 +24,7 @@
 using System;
 using System.Threading.Tasks;
 using OpenTween.Connection;
-using OpenTween.Models;
+using OpenTween.SocialProtocol.Twitter;
 
 namespace OpenTween.Api.GraphQL
 {
diff --git a/OpenTween/Api/GraphQL/DeleteTweetRequest.cs b/OpenTween/Api/GraphQL/DeleteTweetRequest.cs
index db3b28c63..988b40ed7 100644
--- a/OpenTween/Api/GraphQL/DeleteTweetRequest.cs
+++ b/OpenTween/Api/GraphQL/DeleteTweetRequest.cs
@@ -24,7 +24,7 @@
 using System;
 using System.Threading.Tasks;
 using OpenTween.Connection;
-using OpenTween.Models;
+using OpenTween.SocialProtocol.Twitter;
 
 namespace OpenTween.Api.GraphQL
 {
diff --git a/OpenTween/Api/GraphQL/FavoriteTweetRequest.cs b/OpenTween/Api/GraphQL/FavoriteTweetRequest.cs
index 1abe7ecf3..a2abf1075 100644
--- a/OpenTween/Api/GraphQL/FavoriteTweetRequest.cs
+++ b/OpenTween/Api/GraphQL/FavoriteTweetRequest.cs
@@ -24,7 +24,7 @@
 using System;
 using System.Threading.Tasks;
 using OpenTween.Connection;
-using OpenTween.Models;
+using OpenTween.SocialProtocol.Twitter;
 
 namespace OpenTween.Api.GraphQL
 {
diff --git a/OpenTween/Api/GraphQL/LikesRequest.cs b/OpenTween/Api/GraphQL/LikesRequest.cs
index 31dd29402..745ba8e6a 100644
--- a/OpenTween/Api/GraphQL/LikesRequest.cs
+++ b/OpenTween/Api/GraphQL/LikesRequest.cs
@@ -25,7 +25,7 @@
 using System.Collections.Generic;
 using System.Threading.Tasks;
 using OpenTween.Connection;
-using OpenTween.Models;
+using OpenTween.SocialProtocol.Twitter;
 
 namespace OpenTween.Api.GraphQL
 {
diff --git a/OpenTween/Api/GraphQL/TweetDetailRequest.cs b/OpenTween/Api/GraphQL/TweetDetailRequest.cs
index b8c4151d3..4ce2a08f2 100644
--- a/OpenTween/Api/GraphQL/TweetDetailRequest.cs
+++ b/OpenTween/Api/GraphQL/TweetDetailRequest.cs
@@ -25,7 +25,7 @@
 using System.Collections.Generic;
 using System.Threading.Tasks;
 using OpenTween.Connection;
-using OpenTween.Models;
+using OpenTween.SocialProtocol.Twitter;
 
 namespace OpenTween.Api.GraphQL
 {
diff --git a/OpenTween/Api/GraphQL/UnfavoriteTweetRequest.cs b/OpenTween/Api/GraphQL/UnfavoriteTweetRequest.cs
index c952da207..1fac0a79e 100644
--- a/OpenTween/Api/GraphQL/UnfavoriteTweetRequest.cs
+++ b/OpenTween/Api/GraphQL/UnfavoriteTweetRequest.cs
@@ -24,7 +24,7 @@
 using System;
 using System.Threading.Tasks;
 using OpenTween.Connection;
-using OpenTween.Models;
+using OpenTween.SocialProtocol.Twitter;
 
 namespace OpenTween.Api.GraphQL
 {
diff --git a/OpenTween/Api/GraphQL/UserTweetsAndRepliesRequest.cs b/OpenTween/Api/GraphQL/UserTweetsAndRepliesRequest.cs
index f5d629fba..bef0ed663 100644
--- a/OpenTween/Api/GraphQL/UserTweetsAndRepliesRequest.cs
+++ b/OpenTween/Api/GraphQL/UserTweetsAndRepliesRequest.cs
@@ -25,7 +25,7 @@
 using System.Collections.Generic;
 using System.Threading.Tasks;
 using OpenTween.Connection;
-using OpenTween.Models;
+using OpenTween.SocialProtocol.Twitter;
 
 namespace OpenTween.Api.GraphQL
 {
diff --git a/OpenTween/Api/TwitterApi.cs b/OpenTween/Api/TwitterApi.cs
index a53d070f1..bd4aa41a0 100644
--- a/OpenTween/Api/TwitterApi.cs
+++ b/OpenTween/Api/TwitterApi.cs
@@ -31,7 +31,6 @@
 using System.Threading.Tasks;
 using OpenTween.Api.DataModel;
 using OpenTween.Connection;
-using OpenTween.Models;
 using OpenTween.SocialProtocol.Twitter;
 
 namespace OpenTween.Api
diff --git a/OpenTween/Api/TwitterV2/GetTimelineRequest.cs b/OpenTween/Api/TwitterV2/GetTimelineRequest.cs
index 24faa6b23..c246246c5 100644
--- a/OpenTween/Api/TwitterV2/GetTimelineRequest.cs
+++ b/OpenTween/Api/TwitterV2/GetTimelineRequest.cs
@@ -28,7 +28,7 @@
 using System.Threading.Tasks;
 using OpenTween.Api.DataModel;
 using OpenTween.Connection;
-using OpenTween.Models;
+using OpenTween.SocialProtocol.Twitter;
 
 namespace OpenTween.Api.TwitterV2
 {
diff --git a/OpenTween/ListElement.cs b/OpenTween/ListElement.cs
index 5344e2722..70f032e37 100644
--- a/OpenTween/ListElement.cs
+++ b/OpenTween/ListElement.cs
@@ -31,6 +31,7 @@
 using System.Xml.Serialization;
 using OpenTween.Api.DataModel;
 using OpenTween.Models;
+using OpenTween.SocialProtocol.Twitter;
 
 namespace OpenTween
 {
diff --git a/OpenTween/Models/TabInformations.cs b/OpenTween/Models/TabInformations.cs
index 89110aff7..d3030dad6 100644
--- a/OpenTween/Models/TabInformations.cs
+++ b/OpenTween/Models/TabInformations.cs
@@ -37,6 +37,7 @@
 using System.Windows.Forms;
 using OpenTween.Setting;
 using OpenTween.SocialProtocol;
+using OpenTween.SocialProtocol.Twitter;
 
 namespace OpenTween.Models
 {
diff --git a/OpenTween/MyCommon.cs b/OpenTween/MyCommon.cs
index 71e24a571..c29b30311 100644
--- a/OpenTween/MyCommon.cs
+++ b/OpenTween/MyCommon.cs
@@ -51,7 +51,6 @@
 using System.Threading.Tasks;
 using System.Web;
 using System.Windows.Forms;
-using OpenTween.Models;
 using OpenTween.Setting;
 using OpenTween.SocialProtocol.Twitter;
 
diff --git a/OpenTween/SocialProtocol/InvalidAccount.cs b/OpenTween/SocialProtocol/InvalidAccount.cs
index 24d31a23d..4c47ac620 100644
--- a/OpenTween/SocialProtocol/InvalidAccount.cs
+++ b/OpenTween/SocialProtocol/InvalidAccount.cs
@@ -26,6 +26,7 @@
 using OpenTween.Api;
 using OpenTween.Connection;
 using OpenTween.Models;
+using OpenTween.SocialProtocol.Twitter;
 
 namespace OpenTween.SocialProtocol
 {
diff --git a/OpenTween/SocialProtocol/Misskey/MisskeyPostFactory.cs b/OpenTween/SocialProtocol/Misskey/MisskeyPostFactory.cs
index 743341a95..f4296e60a 100644
--- a/OpenTween/SocialProtocol/Misskey/MisskeyPostFactory.cs
+++ b/OpenTween/SocialProtocol/Misskey/MisskeyPostFactory.cs
@@ -28,6 +28,7 @@
 using OpenTween.Api.Misskey;
 using OpenTween.Models;
 using OpenTween.Setting;
+using OpenTween.SocialProtocol.Twitter;
 using OpenTween.Thumbnail;
 
 namespace OpenTween.SocialProtocol.Misskey
diff --git a/OpenTween/Models/TwitterDirectMessageId.cs b/OpenTween/SocialProtocol/Twitter/TwitterDirectMessageId.cs
similarity index 94%
rename from OpenTween/Models/TwitterDirectMessageId.cs
rename to OpenTween/SocialProtocol/Twitter/TwitterDirectMessageId.cs
index 13d3fdbf3..cb6278485 100644
--- a/OpenTween/Models/TwitterDirectMessageId.cs
+++ b/OpenTween/SocialProtocol/Twitter/TwitterDirectMessageId.cs
@@ -22,8 +22,9 @@
 #nullable enable
 
 using System;
+using OpenTween.Models;
 
-namespace OpenTween.Models
+namespace OpenTween.SocialProtocol.Twitter
 {
     public class TwitterDirectMessageId : PostId
     {
diff --git a/OpenTween/Models/TwitterPostFactory.cs b/OpenTween/SocialProtocol/Twitter/TwitterPostFactory.cs
similarity index 99%
rename from OpenTween/Models/TwitterPostFactory.cs
rename to OpenTween/SocialProtocol/Twitter/TwitterPostFactory.cs
index dba5b3c39..8a9a71f28 100644
--- a/OpenTween/Models/TwitterPostFactory.cs
+++ b/OpenTween/SocialProtocol/Twitter/TwitterPostFactory.cs
@@ -23,14 +23,13 @@
 
 using System;
 using System.Collections.Generic;
-using System.Globalization;
 using System.Linq;
 using System.Net;
 using System.Text.RegularExpressions;
 using OpenTween.Api.DataModel;
-using OpenTween.Setting;
+using OpenTween.Models;
 
-namespace OpenTween.Models
+namespace OpenTween.SocialProtocol.Twitter
 {
     public class TwitterPostFactory
     {
@@ -402,7 +401,7 @@ private static string CreateAccessibleText(string text, TwitterEntities? entitie
                 {
                     if (quotedStatus != null)
                     {
-                        var matchStatusUrl = Twitter.StatusUrlRegex.Match(entity.ExpandedUrl);
+                        var matchStatusUrl = OpenTween.Twitter.StatusUrlRegex.Match(entity.ExpandedUrl);
                         if (matchStatusUrl.Success && matchStatusUrl.Groups["StatusId"].Value == quotedStatus.IdStr)
                         {
                             var quotedText = CreateAccessibleText(quotedStatus.FullText, quotedStatus.MergedEntities, quotedStatus: null, quotedStatusLink: null);
@@ -553,7 +552,7 @@ public static IEnumerable<TwitterStatusId> GetQuoteTweetStatusIds(IEnumerable<st
         {
             foreach (var url in urls)
             {
-                var match = Twitter.StatusUrlRegex.Match(url);
+                var match = OpenTween.Twitter.StatusUrlRegex.Match(url);
                 if (match.Success)
                     yield return new(match.Groups["StatusId"].Value);
             }
diff --git a/OpenTween/Models/TwitterStatusId.cs b/OpenTween/SocialProtocol/Twitter/TwitterStatusId.cs
similarity index 96%
rename from OpenTween/Models/TwitterStatusId.cs
rename to OpenTween/SocialProtocol/Twitter/TwitterStatusId.cs
index 0774bde14..0e34cae7f 100644
--- a/OpenTween/Models/TwitterStatusId.cs
+++ b/OpenTween/SocialProtocol/Twitter/TwitterStatusId.cs
@@ -22,8 +22,9 @@
 #nullable enable
 
 using System;
+using OpenTween.Models;
 
-namespace OpenTween.Models
+namespace OpenTween.SocialProtocol.Twitter
 {
     public class TwitterStatusId : PostId
     {
diff --git a/OpenTween/Models/TwitterUserId.cs b/OpenTween/SocialProtocol/Twitter/TwitterUserId.cs
similarity index 94%
rename from OpenTween/Models/TwitterUserId.cs
rename to OpenTween/SocialProtocol/Twitter/TwitterUserId.cs
index 6020e0799..08da1d389 100644
--- a/OpenTween/Models/TwitterUserId.cs
+++ b/OpenTween/SocialProtocol/Twitter/TwitterUserId.cs
@@ -22,8 +22,9 @@
 #nullable enable
 
 using System;
+using OpenTween.Models;
 
-namespace OpenTween.Models
+namespace OpenTween.SocialProtocol.Twitter
 {
     public class TwitterUserId : PersonId
     {
diff --git a/OpenTween/TimelineListViewState.cs b/OpenTween/TimelineListViewState.cs
index 5625414f8..36f6a6a1c 100644
--- a/OpenTween/TimelineListViewState.cs
+++ b/OpenTween/TimelineListViewState.cs
@@ -27,7 +27,6 @@
 #nullable enable
 
 using System;
-using System.Collections.Generic;
 using System.Drawing;
 using System.Linq;
 using System.Windows.Forms;
diff --git a/OpenTween/UserInfo.cs b/OpenTween/UserInfo.cs
index 4369c4b6d..a725fbdd1 100644
--- a/OpenTween/UserInfo.cs
+++ b/OpenTween/UserInfo.cs
@@ -30,6 +30,7 @@
 using System.Net;
 using OpenTween.Api.DataModel;
 using OpenTween.Models;
+using OpenTween.SocialProtocol.Twitter;
 
 namespace OpenTween
 {
diff --git a/OpenTween/UserInfoDialog.cs b/OpenTween/UserInfoDialog.cs
index d07eff942..339b0ff31 100644
--- a/OpenTween/UserInfoDialog.cs
+++ b/OpenTween/UserInfoDialog.cs
@@ -27,24 +27,18 @@
 #nullable enable
 
 using System;
-using System.Collections.Generic;
 using System.ComponentModel;
 using System.Data;
 using System.Diagnostics.CodeAnalysis;
-using System.Drawing;
 using System.IO;
 using System.Linq;
-using System.Net;
-using System.Text;
-using System.Text.RegularExpressions;
 using System.Threading;
 using System.Threading.Tasks;
-using System.Web;
 using System.Windows.Forms;
-using OpenTween.Api;
 using OpenTween.Api.DataModel;
 using OpenTween.Connection;
 using OpenTween.Models;
+using OpenTween.SocialProtocol.Twitter;
 
 namespace OpenTween
 {