diff --git a/android/app/src/main/java/com/goliath/emojihub/RootActivity.kt b/android/app/src/main/java/com/goliath/emojihub/RootActivity.kt
index 6f700095..a2df9fe6 100644
--- a/android/app/src/main/java/com/goliath/emojihub/RootActivity.kt
+++ b/android/app/src/main/java/com/goliath/emojihub/RootActivity.kt
@@ -15,6 +15,7 @@ import androidx.compose.runtime.remember
 import androidx.compose.ui.Modifier
 import androidx.compose.ui.graphics.Color
 import androidx.hilt.navigation.compose.hiltViewModel
+import androidx.navigation.NavController
 import androidx.navigation.NavGraphBuilder
 import androidx.navigation.compose.NavHost
 import androidx.navigation.compose.composable
@@ -110,12 +111,18 @@ class RootActivity : ComponentActivity() {
                 }
 
                 composable(NavigationDestination.TransformVideo) {
-                    val emojiViewModel = hiltViewModel<EmojiViewModel>()
+                    val parentEntry = remember(it) {
+                        navController.getBackStackEntry(NavigationDestination.MainPage)
+                    }
+                    val emojiViewModel = hiltViewModel<EmojiViewModel>(parentEntry)
                     TransformVideoPage(emojiViewModel)
                 }
 
                 composable(NavigationDestination.PlayEmojiVideo) {
-                    val emojiViewModel = hiltViewModel<EmojiViewModel>()
+                    val parentEntry = remember(it) {
+                        navController.getBackStackEntry(NavigationDestination.MainPage)
+                    }
+                    val emojiViewModel = hiltViewModel<EmojiViewModel>(parentEntry)
                     PlayEmojiView(emojiViewModel)
                 }
 
@@ -126,4 +133,12 @@ class RootActivity : ComponentActivity() {
             }
         }
     }
+}
+
+fun NavController.navigateAsOrigin(route: String) {
+    navigate(route) {
+        while (popBackStack()) { }
+        launchSingleTop = true
+        restoreState = true
+    }
 }
\ No newline at end of file
diff --git a/android/app/src/main/java/com/goliath/emojihub/data_sources/BottomNavigationController.kt b/android/app/src/main/java/com/goliath/emojihub/data_sources/BottomNavigationController.kt
index d8ea772f..77ec7b80 100644
--- a/android/app/src/main/java/com/goliath/emojihub/data_sources/BottomNavigationController.kt
+++ b/android/app/src/main/java/com/goliath/emojihub/data_sources/BottomNavigationController.kt
@@ -1,7 +1,7 @@
 package com.goliath.emojihub.data_sources
 
-import androidx.compose.runtime.MutableState
 import androidx.compose.runtime.Stable
+import androidx.compose.runtime.State
 import androidx.compose.runtime.mutableStateOf
 import com.goliath.emojihub.views.PageItem
 
@@ -9,7 +9,7 @@ class BottomNavigationController {
     private val _bottomNavigationDestination = mutableStateOf(PageItem.Feed.screenRoute)
 
     @Stable
-    val currentDestination: MutableState<String> = _bottomNavigationDestination
+    val currentDestination: State<String> = _bottomNavigationDestination
 
     fun updateDestination(destination: PageItem) {
         _bottomNavigationDestination.value = destination.screenRoute
diff --git a/android/app/src/main/java/com/goliath/emojihub/viewmodels/EmojiViewModel.kt b/android/app/src/main/java/com/goliath/emojihub/viewmodels/EmojiViewModel.kt
index 6ac0a5c8..4c2d4096 100644
--- a/android/app/src/main/java/com/goliath/emojihub/viewmodels/EmojiViewModel.kt
+++ b/android/app/src/main/java/com/goliath/emojihub/viewmodels/EmojiViewModel.kt
@@ -16,6 +16,7 @@ import dagger.hilt.android.lifecycle.HiltViewModel
 import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.flow.MutableStateFlow
 import kotlinx.coroutines.flow.asStateFlow
+import kotlinx.coroutines.flow.update
 import kotlinx.coroutines.launch
 import kotlinx.coroutines.withContext
 import java.io.File
@@ -26,7 +27,7 @@ class EmojiViewModel @Inject constructor(
     private val emojiUseCase: EmojiUseCase
 ): ViewModel() {
     lateinit var videoUri: Uri
-    var currentEmoji: Emoji? = null
+    lateinit var currentEmoji: Emoji
     var bottomSheetContent by mutableStateOf(BottomSheetContent.EMPTY)
 
     private val _saveEmojiState = MutableStateFlow<Result<Unit>?>(null)
@@ -38,6 +39,7 @@ class EmojiViewModel @Inject constructor(
     val emojiList = emojiUseCase.emojiList
     val myCreatedEmojiList = emojiUseCase.myCreatedEmojiList
     val mySavedEmojiList = emojiUseCase.mySavedEmojiList
+
     companion object {
         private const val _topK = 3
     }
@@ -93,8 +95,8 @@ class EmojiViewModel @Inject constructor(
 
     fun unSaveEmoji(id: String) {
         viewModelScope.launch {
-        val result = emojiUseCase.unSaveEmoji(id)
-        _unSaveEmojiState.value = result
+            val result = emojiUseCase.unSaveEmoji(id)
+            _unSaveEmojiState.value = result
         }
     }
 }
\ No newline at end of file
diff --git a/android/app/src/main/java/com/goliath/emojihub/views/EmojiPage.kt b/android/app/src/main/java/com/goliath/emojihub/views/EmojiPage.kt
index 2b2ac6db..39b6184c 100644
--- a/android/app/src/main/java/com/goliath/emojihub/views/EmojiPage.kt
+++ b/android/app/src/main/java/com/goliath/emojihub/views/EmojiPage.kt
@@ -62,8 +62,7 @@ fun EmojiPage(
 
     val emojiList = viewModel.emojiList.collectAsLazyPagingItems()
 
-    LaunchedEffect(Unit)
-    {
+    LaunchedEffect(Unit) {
         viewModel.fetchEmojiList()
     }
 
@@ -79,9 +78,7 @@ fun EmojiPage(
                         ))
                     }
                     else -> {
-                        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.TIRAMISU) {
-                            permissionLauncher.launch(Manifest.permission.READ_MEDIA_VIDEO)
-                        }
+                        permissionLauncher.launch(Manifest.permission.READ_MEDIA_VIDEO)
                     }
                 }
             }) {
diff --git a/android/app/src/main/java/com/goliath/emojihub/views/LoginPage.kt b/android/app/src/main/java/com/goliath/emojihub/views/LoginPage.kt
index ef675dec..05b1b3ab 100644
--- a/android/app/src/main/java/com/goliath/emojihub/views/LoginPage.kt
+++ b/android/app/src/main/java/com/goliath/emojihub/views/LoginPage.kt
@@ -37,6 +37,7 @@ import androidx.hilt.navigation.compose.hiltViewModel
 import com.goliath.emojihub.LocalNavController
 import com.goliath.emojihub.NavigationDestination
 import com.goliath.emojihub.R
+import com.goliath.emojihub.navigateAsOrigin
 import com.goliath.emojihub.ui.theme.Color
 import com.goliath.emojihub.viewmodels.UserViewModel
 import com.goliath.emojihub.views.components.UnderlinedTextField
@@ -133,7 +134,7 @@ fun LoginPage() {
                 color = Color.DarkGray,
                 style = TextStyle(textDecoration = TextDecoration.Underline),
                 modifier = Modifier.clickable {
-                    navController.navigate(NavigationDestination.MainPage)
+                    navController.navigateAsOrigin(NavigationDestination.MainPage)
                 }
             )
             Spacer(modifier = Modifier.height(24.dp))
diff --git a/android/app/src/main/java/com/goliath/emojihub/views/MainPage.kt b/android/app/src/main/java/com/goliath/emojihub/views/MainPage.kt
index c6cdd681..875ea166 100644
--- a/android/app/src/main/java/com/goliath/emojihub/views/MainPage.kt
+++ b/android/app/src/main/java/com/goliath/emojihub/views/MainPage.kt
@@ -31,9 +31,7 @@ fun MainPage() {
             pageItemList.forEach { pageItem ->
                 BottomNavigationItem(
                     selected = currentRoute == pageItem.screenRoute,
-                    onClick = {
-                        bottomNavigationController.updateDestination(pageItem)
-                    },
+                    onClick = { bottomNavigationController.updateDestination(pageItem) },
                     icon = {
                         Icon(
                             painter = painterResource(id = pageItem.icon),
diff --git a/android/app/src/main/java/com/goliath/emojihub/views/ProfilePage.kt b/android/app/src/main/java/com/goliath/emojihub/views/ProfilePage.kt
index 5e473e12..56a743a5 100644
--- a/android/app/src/main/java/com/goliath/emojihub/views/ProfilePage.kt
+++ b/android/app/src/main/java/com/goliath/emojihub/views/ProfilePage.kt
@@ -29,6 +29,7 @@ import androidx.hilt.navigation.compose.hiltViewModel
 import androidx.paging.compose.collectAsLazyPagingItems
 import com.goliath.emojihub.LocalNavController
 import com.goliath.emojihub.NavigationDestination
+import com.goliath.emojihub.navigateAsOrigin
 import com.goliath.emojihub.ui.theme.Color
 import com.goliath.emojihub.ui.theme.Color.EmojiHubDetailLabel
 import com.goliath.emojihub.ui.theme.Color.White
@@ -173,7 +174,10 @@ fun ProfilePage() {
                     needsCancelButton = true,
                     onDismissRequest = { showLogoutDialog = false },
                     dismiss = { showLogoutDialog = false },
-                    confirm = { userViewModel.logout() }
+                    confirm = {
+                        navController.navigateAsOrigin(NavigationDestination.Onboard)
+                        userViewModel.logout()
+                    }
                 )
             }
 
@@ -186,7 +190,10 @@ fun ProfilePage() {
                     needsCancelButton = true,
                     onDismissRequest = { showSignOutDialog = false },
                     dismiss = { showSignOutDialog = false },
-                    confirm = { userViewModel.signOut() }
+                    confirm = {
+                        navController.navigateAsOrigin(NavigationDestination.Onboard)
+                        userViewModel.signOut()
+                    }
                 )
             }
         }
diff --git a/android/app/src/main/java/com/goliath/emojihub/views/components/CustomBottomSheet.kt b/android/app/src/main/java/com/goliath/emojihub/views/components/CustomBottomSheet.kt
index 4adb5b38..ffc63c81 100644
--- a/android/app/src/main/java/com/goliath/emojihub/views/components/CustomBottomSheet.kt
+++ b/android/app/src/main/java/com/goliath/emojihub/views/components/CustomBottomSheet.kt
@@ -1,6 +1,5 @@
 package com.goliath.emojihub.views.components
 
-import android.util.Log
 import androidx.compose.foundation.layout.Arrangement
 import androidx.compose.foundation.layout.Column
 import androidx.compose.foundation.layout.Row
@@ -58,7 +57,6 @@ fun CustomBottomSheet (
     val bottomSheetState = LocalBottomSheetController.current
     val coroutineScope = rememberCoroutineScope()
     val viewModel = hiltViewModel<EmojiViewModel>()
-    val navController = LocalNavController.current
 
     var selectedEmojiClass by remember { mutableStateOf<String?>("전체") }
     val emojisByClass = emojiList.groupBy { it.unicode }
@@ -174,10 +172,11 @@ fun CustomBottomSheet (
                     BottomSheetContent.EMPTY -> {}
 
                     BottomSheetContent.VIEW_REACTION -> {
-                        items(if (selectedEmojiClass == "전체") emojiList else emojiList.filter { it.unicode == selectedEmojiClass }, key = { it.id }) { emoji ->
+                        items(
+                            if (selectedEmojiClass == "전체") emojiList
+                            else emojiList.filter { it.unicode == selectedEmojiClass }, key = { it.id }) { emoji ->
                             EmojiCell(emoji = emoji, displayMode = EmojiCellDisplay.VERTICAL) {selectedEmoji ->
-                                viewModel.currentEmoji = selectedEmoji
-                                navController.navigate(NavigationDestination.PlayEmojiVideo) //FIXME: make a new destination or fix PlayEmojiVideo's back stack to include BottomSheet
+                                emojiCellClicked(selectedEmoji)
                             }
                         }
                     }
diff --git a/android/app/src/main/java/com/goliath/emojihub/views/components/EmptyProfile.kt b/android/app/src/main/java/com/goliath/emojihub/views/components/EmptyProfile.kt
index 4e057e39..5465dabd 100644
--- a/android/app/src/main/java/com/goliath/emojihub/views/components/EmptyProfile.kt
+++ b/android/app/src/main/java/com/goliath/emojihub/views/components/EmptyProfile.kt
@@ -21,6 +21,7 @@ import androidx.compose.ui.unit.dp
 import androidx.compose.ui.unit.sp
 import com.goliath.emojihub.LocalNavController
 import com.goliath.emojihub.NavigationDestination
+import com.goliath.emojihub.navigateAsOrigin
 import com.goliath.emojihub.ui.theme.Color
 
 @Composable
@@ -54,7 +55,7 @@ fun EmptyProfile() {
         }
         Spacer(modifier = Modifier.weight(1f))
         Button(
-            onClick = { navController.navigate(NavigationDestination.Onboard) },
+            onClick = { navController.navigateAsOrigin(NavigationDestination.Onboard) },
             modifier = Modifier.fillMaxWidth().height(44.dp),
             shape = RoundedCornerShape(50),
             colors = ButtonDefaults.buttonColors(
diff --git a/android/app/src/main/java/com/goliath/emojihub/views/components/PlayEmojiView.kt b/android/app/src/main/java/com/goliath/emojihub/views/components/PlayEmojiView.kt
index 5327e414..472113ff 100644
--- a/android/app/src/main/java/com/goliath/emojihub/views/components/PlayEmojiView.kt
+++ b/android/app/src/main/java/com/goliath/emojihub/views/components/PlayEmojiView.kt
@@ -1,6 +1,5 @@
 package com.goliath.emojihub.views.components
 
-import android.util.Log
 import android.widget.Toast
 import androidx.compose.foundation.background
 import androidx.compose.foundation.layout.Box
@@ -20,9 +19,9 @@ import androidx.compose.material.icons.filled.FileDownloadOff
 import androidx.compose.runtime.Composable
 import androidx.compose.runtime.DisposableEffect
 import androidx.compose.runtime.getValue
+import androidx.compose.runtime.mutableIntStateOf
 import androidx.compose.runtime.mutableStateOf
 import androidx.compose.runtime.remember
-import androidx.compose.runtime.rememberCoroutineScope
 import androidx.compose.runtime.setValue
 import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
@@ -36,24 +35,25 @@ import androidx.compose.ui.viewinterop.AndroidView
 import androidx.media3.common.MediaItem
 import androidx.media3.common.Player
 import androidx.media3.exoplayer.ExoPlayer
+import androidx.media3.ui.AspectRatioFrameLayout
+import androidx.media3.ui.AspectRatioFrameLayout.ResizeMode
 import androidx.media3.ui.PlayerView
 import com.goliath.emojihub.LocalNavController
 import com.goliath.emojihub.extensions.toEmoji
 import com.goliath.emojihub.ui.theme.Color
 import com.goliath.emojihub.viewmodels.EmojiViewModel
-import kotlinx.coroutines.launch
 
+@androidx.annotation.OptIn(androidx.media3.common.util.UnstableApi::class)
 @Composable
 fun PlayEmojiView(
     viewModel: EmojiViewModel
 ) {
-    // Play video
     val context = LocalContext.current
     val navController = LocalNavController.current
 
-    val currentEmoji = viewModel.currentEmoji!!
+    val currentEmoji = viewModel.currentEmoji
 
-    var savedCount by remember { mutableStateOf(currentEmoji.savedCount) }
+    var savedCount by remember { mutableIntStateOf(currentEmoji.savedCount) }
     var isSaved by remember { mutableStateOf(currentEmoji.isSaved) }
     var showUnSaveDialog by remember { mutableStateOf(false) }
 
@@ -72,9 +72,7 @@ fun PlayEmojiView(
         }
     }
 
-    Box(
-        Modifier
-            .fillMaxSize()
+    Box(Modifier.fillMaxSize()
             .background(
                 brush = Brush.verticalGradient(listOf(Color.Transparent, Color.Black)),
                 shape = RectangleShape,
@@ -85,6 +83,7 @@ fun PlayEmojiView(
             modifier = Modifier.fillMaxSize(),
             factory = {
                 PlayerView(it).apply {
+                    this.resizeMode = AspectRatioFrameLayout.RESIZE_MODE_FILL
                     player = exoPlayer
                 }
             }
@@ -93,6 +92,7 @@ fun PlayEmojiView(
         TopNavigationBar(
             title = "@" + currentEmoji.createdBy,
             largeTitle = false,
+            needsElevation = false,
             navigate = { navController.popBackStack() }
         ) {}
 
@@ -149,7 +149,6 @@ fun PlayEmojiView(
                         fontSize = 28.sp,
                     )
                 }
-
                 Spacer(modifier = Modifier.padding(bottom = 32.dp))
             }
         }
diff --git a/android/app/src/main/java/com/goliath/emojihub/views/components/TopNavigationBar.kt b/android/app/src/main/java/com/goliath/emojihub/views/components/TopNavigationBar.kt
index 63353cef..1b1a490e 100644
--- a/android/app/src/main/java/com/goliath/emojihub/views/components/TopNavigationBar.kt
+++ b/android/app/src/main/java/com/goliath/emojihub/views/components/TopNavigationBar.kt
@@ -28,13 +28,14 @@ fun TopNavigationBar(
     title: String = "",
     largeTitle: Boolean = true,
     shouldNavigate: Boolean = true,
+    needsElevation: Boolean = true,
     navigate: () -> Unit = {},
     actions: @Composable () -> Unit = {},
 ) {
     Surface(
         color = Color.Transparent,
         shape = RectangleShape,
-        elevation = 1.dp,
+        elevation = if (needsElevation) 1.dp else 0.dp,
         modifier = Modifier.height(64.dp),
     ) {
         Box(Modifier.padding(horizontal = 4.dp)) {