diff --git a/app/Plugins/User/Photoalbums/PhotoalbumsPlugin.php b/app/Plugins/User/Photoalbums/PhotoalbumsPlugin.php
index 174e0dc69..f28efdb17 100644
--- a/app/Plugins/User/Photoalbums/PhotoalbumsPlugin.php
+++ b/app/Plugins/User/Photoalbums/PhotoalbumsPlugin.php
@@ -154,7 +154,10 @@ public function index($request, $page_id, $frame_id, $parent_id = null)
         }
 
         // カバー写真に指定されている写真
-        $covers = PhotoalbumContent::whereIn('parent_id', $photoalbum_contents->where('is_folder', PhotoalbumContent::is_folder_on)->pluck('id'))->where('is_cover', PhotoalbumContent::is_cover_on)->get();
+        $covers = PhotoalbumContent::whereIn('parent_id', $photoalbum_contents->where('is_folder', PhotoalbumContent::is_folder_on)->pluck('id'))
+            ->where('is_cover', PhotoalbumContent::is_cover_on)
+            ->with(['upload', 'posterUpload'])
+            ->get();
 
         // 表示テンプレートを呼び出す。
         return $this->view('index', [
@@ -375,7 +378,7 @@ private function isHiddenPhotoalbumContent(PhotoalbumContent $content, array $hi
     private function getSortedChildren(PhotoalbumContent $parent, ?string $sort_folder, ?string $sort_file, ?Collection $preloaded_children = null)
     {
         $children = is_null($preloaded_children)
-            ? $parent->children()->get()
+            ? $parent->children()->with(['upload', 'posterUpload'])->get()
             : $preloaded_children->get($parent->id, collect());
 
         // 設定画面などで事前に読み込んだ子要素一覧を再利用し、追加クエリを避ける
diff --git a/app/Providers/AppServiceProvider.php b/app/Providers/AppServiceProvider.php
index 3d850f778..29dec0dee 100644
--- a/app/Providers/AppServiceProvider.php
+++ b/app/Providers/AppServiceProvider.php
@@ -541,7 +541,19 @@ private function getPostBucketsRoles($buckets)
             return false;
         }
 
-        // return $buckets->getBucketsRoles();
+        $request = app(Request::class);
+        $bucket_id = $buckets->id ?? null;
+        // GETは読み取り専用のため、同一リクエスト内キャッシュでSQLを減らしても整合性に影響しない。
+        // POST系は同一リクエスト内で権限やバケツ設定が更新される可能性があるためキャッシュしない。
+        if ($bucket_id && $request->isMethod('get')) {
+            static $cached_post_roles = [];
+            if (array_key_exists($bucket_id, $cached_post_roles)) {
+                return $cached_post_roles[$bucket_id];
+            }
+            $cached_post_roles[$bucket_id] = $buckets->getPostArrayBucketsRoles();
+            return $cached_post_roles[$bucket_id];
+        }
+
         return $buckets->getPostArrayBucketsRoles();
 
         // // Buckets にrole がない場合などで、Buckets のrole を使用しない場合はfalse を返す。
diff --git a/resources/views/plugins/user/photoalbums/card/index_folder.blade.php b/resources/views/plugins/user/photoalbums/card/index_folder.blade.php
index 615038da0..ba99602e2 100644
--- a/resources/views/plugins/user/photoalbums/card/index_folder.blade.php
+++ b/resources/views/plugins/user/photoalbums/card/index_folder.blade.php
@@ -28,6 +28,8 @@
                          id="cover_{{$loop->iteration}}"
                          style="max-height: 200px; object-fit: scale-down; cursor:pointer; border-radius: 3px;"
                          class="img-fluid"
+                         loading="lazy"
+                         decoding="async"
                     >
                 @else
                     <svg class="bd-placeholder-img card-img-top" width="100%" height="150" xmlns="http://www.w3.org/2000/svg" preserveAspectRatio="xMidYMid slice" focusable="false" role="img" aria-label="Placeholder: Image cap">
diff --git a/resources/views/plugins/user/photoalbums/default/index_folder.blade.php b/resources/views/plugins/user/photoalbums/default/index_folder.blade.php
index b1265f75b..82a951163 100644
--- a/resources/views/plugins/user/photoalbums/default/index_folder.blade.php
+++ b/resources/views/plugins/user/photoalbums/default/index_folder.blade.php
@@ -30,6 +30,8 @@
                          id="cover_{{$loop->iteration}}"
                          style="max-height: 200px; object-fit: scale-down; cursor:pointer; border-radius: 3px;"
                          class="img-fluid"
+                         loading="lazy"
+                         decoding="async"
                     >
                 @else
                     <svg class="bd-placeholder-img card-img-top" width="100%" height="150" xmlns="http://www.w3.org/2000/svg" preserveAspectRatio="xMidYMid slice" focusable="false" role="img" aria-label="Placeholder: Image cap">
diff --git a/resources/views/plugins/user/photoalbums/default/index_image.blade.php b/resources/views/plugins/user/photoalbums/default/index_image.blade.php
index d92ccfc70..7823910a3 100644
--- a/resources/views/plugins/user/photoalbums/default/index_image.blade.php
+++ b/resources/views/plugins/user/photoalbums/default/index_image.blade.php
@@ -20,9 +20,13 @@
 $play_view_default = \App\Enums\PhotoalbumPlayviewType::play_in_list;
 $play_view = FrameConfig::getConfigValueAndOld($frame_configs, PhotoalbumFrameConfig::play_view, $play_view_default);
 $description_list_length = FrameConfig::getConfigValueAndOld($frame_configs, PhotoalbumFrameConfig::description_list_length);
+$image_modal_id = 'photoalbum-image-modal-' . $frame_id;
 @endphp
 <div class="row">
     @foreach($photoalbum_contents->where('is_folder', 0) as $photoalbum_content)
+    @php
+        $description_attr = str_replace(["\r\n", "\r", "\n"], '\\n', (string) $photoalbum_content->description);
+    @endphp
     <div class="{{$col_class}}">
         <div class="card mt-3 shadow-sm">
         @if ($photoalbum_content->upload->is_image)
@@ -30,39 +34,25 @@
             <img src="{{url('/')}}/file/{{$photoalbum_content->upload_id}}?size=small"
                  id="photo_{{$frame_id}}_{{$loop->iteration}}"
                  style="max-height: 200px; object-fit: scale-down; cursor:pointer; border-radius: 3px;"
-                 class="img-fluid" data-toggle="modal" data-target="#image_Modal_{{$frame_id}}_{{$loop->iteration}}"
+                 class="img-fluid photoalbum-thumbnail"
+                 data-toggle="modal"
+                 data-target="#{{$image_modal_id}}"
+                 data-thumb="{{url('/')}}/file/{{$photoalbum_content->upload_id}}?size=small"
+                 data-full="{{url('/')}}/file/{{$photoalbum_content->upload_id}}"
+                 data-title="{{e($photoalbum_content->name)}}"
+                 data-description="{{e($description_attr)}}"
+                 loading="lazy"
+                 decoding="async"
             >
-            <div class="modal fade" id="image_Modal_{{$frame_id}}_{{$loop->iteration}}" tabindex="-1" role="dialog" aria-labelledby="myLargeModalLabel_{{$frame_id}}_{{$loop->iteration}}">
-                <div class="modal-dialog modal-lg modal-middle">{{-- モーダルウィンドウの縦表示位置を調整・画像を大きく見せる --}}
-                    <div class="modal-content pb-3">
-                        <div class="modal-body mx-auto">
-                            {{-- 拡大表示ウィンドウにも、初期設定でサムネイルを設定しておき、クリック時に実寸画像を読み込みなおす --}}
-                            <img src="{{url('/')}}/file/{{$photoalbum_content->upload_id}}?size=small"
-                                 style="object-fit: scale-down;"
-                                 id="popup_photo_{{$frame_id}}_{{$loop->iteration}}"
-                                 class="img-fluid"/>
-                        </div>
-                        <div class="modal-img_footer">
-                            <h5 class="card-title">{{$photoalbum_content->name}}</h5>
-                            <p class="card-text">{!!nl2br(e($photoalbum_content->description))!!}</p>
-                            <button type="button" class="btn btn-success" data-dismiss="modal">閉じる</button>
-                        </div>
-                    </div>
-                </div>
-            </div>
-            <script>
-            {{-- サムネイル枠のクリックで、実寸画像を読み込む。一覧表示時のネットワーク通信量の軽減対応 --}}
-            $("#photo_{{$frame_id}}_{{$loop->iteration}}").on("click", function() {
-               $("#popup_photo_{{$frame_id}}_{{$loop->iteration}}").attr('src', "{{url('/')}}/file/{{$photoalbum_content->upload_id}}");
-            });
-            </script>
         @elseif ($photoalbum_content->isVideo($photoalbum_content->mimetype) && $play_view == PhotoalbumPlayviewType::play_in_detail)
             {{-- 動画：一覧はサムネイル画像のみで詳細画面で再生する --}}
             <a href="{{url('/')}}/plugin/photoalbums/detail/{{$page->id}}/{{$frame_id}}/{{$photoalbum_content->id}}#frame-{{$frame->id}}">
                 <img src="{{url('/')}}/file/{{$photoalbum_content->poster_upload_id}}"
                      style="width: 100%; max-height: 200px; object-fit: scale-down; cursor:pointer; border-radius: 3px;"
                      id="popup_photo_{{$frame_id}}_{{$loop->iteration}}"
-                     class="img-fluid"/>
+                     class="img-fluid"
+                     loading="lazy"
+                     decoding="async"/>
             </a>
         @elseif ($photoalbum_content->isVideo($photoalbum_content->mimetype))
             {{-- 動画：一覧で再生する --}}
@@ -129,4 +119,66 @@ class="img-fluid"
     </div>
     @endforeach
 </div>
+
+<div class="modal fade" id="{{$image_modal_id}}" tabindex="-1" role="dialog" aria-labelledby="{{$image_modal_id}}-label" aria-hidden="true">
+    <div class="modal-dialog modal-lg modal-middle">{{-- モーダルウィンドウの縦表示位置を調整・画像を大きく見せる --}}
+        <div class="modal-content pb-3">
+            <div class="modal-body mx-auto">
+                {{-- 拡大表示ウィンドウにも、初期設定でサムネイルを設定しておき、クリック時に実寸画像を読み込みなおす --}}
+                <img src="" style="object-fit: scale-down;" class="img-fluid photoalbum-modal-image"/>
+            </div>
+            <div class="modal-img_footer">
+                <h5 class="card-title photoalbum-modal-title"></h5>
+                <p class="card-text photoalbum-modal-description"></p>
+                <button type="button" class="btn btn-success" data-dismiss="modal">閉じる</button>
+            </div>
+        </div>
+    </div>
+</div>
+
+<script>
+$(function () {
+    var modalId = '#{{$image_modal_id}}';
+    var $modal = $(modalId);
+    var $htmlDecoder = $('<textarea />');
+    var decodeHtmlEntities = function (value) {
+        if (!value) {
+            return '';
+        }
+        return $htmlDecoder.html(value).text();
+    };
+    $modal.on('show.bs.modal', function (event) {
+        var $trigger = $(event.relatedTarget);
+        var thumb = $trigger.data('thumb') || '';
+        var full = $trigger.data('full') || '';
+        var title = $trigger.data('title') || '';
+        var description = $trigger.attr('data-description') || '';
+
+        $modal.find('.photoalbum-modal-image').attr('src', thumb);
+        $modal.find('.photoalbum-modal-title').text(title);
+
+        description = decodeHtmlEntities(description.replace(/\\n/g, '\n'));
+        var $description = $modal.find('.photoalbum-modal-description').empty();
+        if (description) {
+            var lines = description.split('\n');
+            $.each(lines, function (index, line) {
+                if (index) {
+                    $description.append('<br>');
+                }
+                $description.append(document.createTextNode(line));
+            });
+        }
+
+        if (full) {
+            requestAnimationFrame(function () {
+                $modal.find('.photoalbum-modal-image').attr('src', full);
+            });
+        }
+    });
+
+    $modal.on('hidden.bs.modal', function () {
+        $modal.find('.photoalbum-modal-image').attr('src', '');
+    });
+});
+</script>
 @endif