diff --git a/DysonNetwork.Pass/Account/AccountServiceGrpc.cs b/DysonNetwork.Pass/Account/AccountServiceGrpc.cs
index d4f235a..6a0a773 100644
--- a/DysonNetwork.Pass/Account/AccountServiceGrpc.cs
+++ b/DysonNetwork.Pass/Account/AccountServiceGrpc.cs
@@ -53,7 +53,8 @@ public class AccountServiceGrpc(
             .FirstOrDefaultAsync(a => a.AutomatedId == automatedId);
 
         if (account == null)
-            throw new RpcException(new Grpc.Core.Status(StatusCode.NotFound, $"Account with automated ID {request.AutomatedId} not found"));
+            throw new RpcException(new Grpc.Core.Status(StatusCode.NotFound,
+                $"Account with automated ID {request.AutomatedId} not found"));
 
         var perk = await subscriptions.GetPerkSubscriptionAsync(account.Id);
         account.PerkSubscription = perk?.ToReference();
@@ -87,8 +88,8 @@ public class AccountServiceGrpc(
         response.Accounts.AddRange(accounts.Select(a => a.ToProtoValue()));
         return response;
     }
-    
-    
+
+
     public override async Task<GetAccountBatchResponse> GetBotAccountBatch(GetBotAccountBatchRequest request,
         ServerCallContext context)
     {
@@ -159,7 +160,8 @@ public class AccountServiceGrpc(
         return response;
     }
 
-    public override async Task<GetAccountBatchResponse> SearchAccount(SearchAccountRequest request, ServerCallContext context)
+    public override async Task<GetAccountBatchResponse> SearchAccount(SearchAccountRequest request,
+        ServerCallContext context)
     {
         var accounts = await _db.Accounts
             .AsNoTracking()
@@ -232,21 +234,48 @@ public class AccountServiceGrpc(
     public override async Task<ListRelationshipSimpleResponse> ListFriends(
         ListRelationshipSimpleRequest request, ServerCallContext context)
     {
-        var accountId = Guid.Parse(request.AccountId);
-        var relationship = await relationships.ListAccountFriends(accountId);
         var resp = new ListRelationshipSimpleResponse();
-        resp.AccountsId.AddRange(relationship.Select(x => x.ToString()));
-        return resp;
+        switch (request.RelationIdentifierCase)
+        {
+            case ListRelationshipSimpleRequest.RelationIdentifierOneofCase.AccountId:
+                var accountId = Guid.Parse(request.AccountId);
+                var relationship = await relationships.ListAccountFriends(accountId);
+                resp.AccountsId.AddRange(relationship.Select(x => x.ToString()));
+                return resp;
+            case ListRelationshipSimpleRequest.RelationIdentifierOneofCase.RelatedId:
+                var relatedId = Guid.Parse(request.RelatedId);
+                var relatedRelationship = await relationships.ListAccountFriends(relatedId, true);
+                resp.AccountsId.AddRange(relatedRelationship.Select(x => x.ToString()));
+                return resp;
+                break;
+            case ListRelationshipSimpleRequest.RelationIdentifierOneofCase.None:
+            default:
+                throw new RpcException(new Status(StatusCode.InvalidArgument,
+                    $"The relationship identifier must be provided."));
+        }
     }
 
     public override async Task<ListRelationshipSimpleResponse> ListBlocked(
         ListRelationshipSimpleRequest request, ServerCallContext context)
     {
-        var accountId = Guid.Parse(request.AccountId);
-        var relationship = await relationships.ListAccountBlocked(accountId);
         var resp = new ListRelationshipSimpleResponse();
-        resp.AccountsId.AddRange(relationship.Select(x => x.ToString()));
-        return resp;
+        switch (request.RelationIdentifierCase)
+        {
+            case ListRelationshipSimpleRequest.RelationIdentifierOneofCase.AccountId:
+                var accountId = Guid.Parse(request.AccountId);
+                var relationship = await relationships.ListAccountBlocked(accountId);
+                resp.AccountsId.AddRange(relationship.Select(x => x.ToString()));
+                return resp;
+            case ListRelationshipSimpleRequest.RelationIdentifierOneofCase.RelatedId:
+                var relatedId = Guid.Parse(request.RelatedId);
+                var relatedRelationship = await relationships.ListAccountBlocked(relatedId, true);
+                resp.AccountsId.AddRange(relatedRelationship.Select(x => x.ToString()));
+                return resp;
+            case ListRelationshipSimpleRequest.RelationIdentifierOneofCase.None:
+            default:
+                throw new RpcException(new Status(StatusCode.InvalidArgument,
+                    $"The relationship identifier must be provided."));
+        }
     }
 
     public override async Task<GetRelationshipResponse> GetRelationship(GetRelationshipRequest request,
diff --git a/DysonNetwork.Pass/Account/RelationshipService.cs b/DysonNetwork.Pass/Account/RelationshipService.cs
index 248f9aa..52002f7 100644
--- a/DysonNetwork.Pass/Account/RelationshipService.cs
+++ b/DysonNetwork.Pass/Account/RelationshipService.cs
@@ -52,7 +52,8 @@ public class RelationshipService(
         return relationship;
     }
 
-    public async Task<SnAccountRelationship> CreateRelationship(SnAccount sender, SnAccount target, RelationshipStatus status)
+    public async Task<SnAccountRelationship> CreateRelationship(SnAccount sender, SnAccount target,
+        RelationshipStatus status)
     {
         if (status == RelationshipStatus.Pending)
             throw new InvalidOperationException(
@@ -169,12 +170,14 @@ public class RelationshipService(
 
         await db.SaveChangesAsync();
 
-        await PurgeRelationshipCache(relationship.AccountId, relationship.RelatedId, RelationshipStatus.Friends, status);
+        await PurgeRelationshipCache(relationship.AccountId, relationship.RelatedId, RelationshipStatus.Friends,
+            status);
 
         return relationshipBackward;
     }
 
-    public async Task<SnAccountRelationship> UpdateRelationship(Guid accountId, Guid relatedId, RelationshipStatus status)
+    public async Task<SnAccountRelationship> UpdateRelationship(Guid accountId, Guid relatedId,
+        RelationshipStatus status)
     {
         var relationship = await GetRelationship(accountId, relatedId);
         if (relationship is null) throw new ArgumentException("There is no relationship between you and the user.");
@@ -189,24 +192,26 @@ public class RelationshipService(
         return relationship;
     }
 
-    public async Task<List<Guid>> ListAccountFriends(SnAccount account)
+    public async Task<List<Guid>> ListAccountFriends(SnAccount account, bool isRelated = false)
     {
-        return await ListAccountFriends(account.Id);
+        return await ListAccountFriends(account.Id, isRelated);
     }
 
-    public async Task<List<Guid>> ListAccountFriends(Guid accountId)
+    public async Task<List<Guid>> ListAccountFriends(Guid accountId, bool isRelated = false)
     {
-        return await GetCachedRelationships(accountId, RelationshipStatus.Friends, UserFriendsCacheKeyPrefix);
+        return await GetCachedRelationships(accountId, RelationshipStatus.Friends, UserFriendsCacheKeyPrefix,
+            isRelated);
     }
 
-    public async Task<List<Guid>> ListAccountBlocked(SnAccount account)
+    public async Task<List<Guid>> ListAccountBlocked(SnAccount account, bool isRelated = false)
     {
-        return await ListAccountBlocked(account.Id);
+        return await ListAccountBlocked(account.Id, isRelated);
     }
 
-    public async Task<List<Guid>> ListAccountBlocked(Guid accountId)
+    public async Task<List<Guid>> ListAccountBlocked(Guid accountId, bool isRelated = false)
     {
-        return await GetCachedRelationships(accountId, RelationshipStatus.Blocked, UserBlockedCacheKeyPrefix);
+        return await GetCachedRelationships(accountId, RelationshipStatus.Blocked, UserBlockedCacheKeyPrefix,
+            isRelated);
     }
 
     public async Task<bool> HasRelationshipWithStatus(Guid accountId, Guid relatedId,
@@ -216,29 +221,26 @@ public class RelationshipService(
         return relationship is not null;
     }
 
-    private async Task<List<Guid>> GetCachedRelationships(Guid accountId, RelationshipStatus status, string cachePrefix)
+    private async Task<List<Guid>> GetCachedRelationships(
+        Guid accountId,
+        RelationshipStatus status,
+        string cachePrefix,
+        bool isRelated = false
+    )
     {
         if (accountId == Guid.Empty)
             throw new ArgumentException("Account ID cannot be empty.");
 
-        var cacheKey = $"{cachePrefix}{accountId}";
+        var cacheKey = $"{cachePrefix}{accountId}:{isRelated}";
         var relationships = await cache.GetAsync<List<Guid>>(cacheKey);
 
         if (relationships != null) return relationships;
         var now = Instant.FromDateTimeUtc(DateTime.UtcNow);
         var query = db.AccountRelationships
-            .Where(r => r.RelatedId == accountId)
+            .Where(r => isRelated ? r.RelatedId == accountId : r.AccountId == accountId)
             .Where(r => r.Status == status)
             .Where(r => r.ExpiredAt == null || r.ExpiredAt > now)
-            .Select(r => r.AccountId);
-
-        if (status == RelationshipStatus.Friends)
-        {
-            var usersBlockedByMe = db.AccountRelationships
-                .Where(r => r.AccountId == accountId && r.Status == RelationshipStatus.Blocked)
-                .Select(r => r.RelatedId);
-            query = query.Except(usersBlockedByMe);
-        }
+            .Select(r => isRelated ? r.AccountId : r.RelatedId);
 
         relationships = await query.ToListAsync();
 
@@ -271,4 +273,4 @@ public class RelationshipService(
         var removeTasks = keysToRemove.Select(key => cache.RemoveAsync(key));
         await Task.WhenAll(removeTasks);
     }
-}
+}
\ No newline at end of file
diff --git a/DysonNetwork.Shared/Proto/account.proto b/DysonNetwork.Shared/Proto/account.proto
index 30cb6bc..b480ccd 100644
--- a/DysonNetwork.Shared/Proto/account.proto
+++ b/DysonNetwork.Shared/Proto/account.proto
@@ -290,8 +290,6 @@ service AccountService {
     rpc ListConnections(ListConnectionsRequest) returns (ListConnectionsResponse) {}
 
     // Relationship Operations
-    rpc ListRelationships(ListRelationshipsRequest) returns (ListRelationshipsResponse) {}
-
     rpc GetRelationship(GetRelationshipRequest) returns (GetRelationshipResponse) {}
     rpc HasRelationship(GetRelationshipRequest) returns (google.protobuf.BoolValue) {}
     rpc ListFriends(ListRelationshipSimpleRequest) returns (ListRelationshipSimpleResponse) {}
@@ -489,7 +487,10 @@ message GetRelationshipResponse {
 }
 
 message ListRelationshipSimpleRequest {
-    string account_id = 1;
+    oneof relation_identifier {
+        string account_id = 1;
+        string related_id = 2;
+    }
 }
 
 message ListRelationshipSimpleResponse {