diff --git a/server/domain/src/form/models.rs b/server/domain/src/form/models.rs
index 6a4190b2..211edd31 100644
--- a/server/domain/src/form/models.rs
+++ b/server/domain/src/form/models.rs
@@ -1,32 +1,22 @@
-use async_trait::async_trait;
 use chrono::{DateTime, Utc};
 #[cfg(test)]
 use common::test_utils::{arbitrary_date_time, arbitrary_opt_date_time, arbitrary_with_size};
 use derive_getters::Getters;
 use deriving_via::DerivingVia;
-use errors::{domain::DomainError, Error};
+use errors::domain::DomainError;
 #[cfg(test)]
 use proptest_derive::Arbitrary;
 use serde::{Deserialize, Serialize};
 use strum_macros::{Display, EnumString};
 use typed_builder::TypedBuilder;
-use types::Resolver;
 
 use crate::{
-    repository::form_repository::FormRepository,
     types::authorization_guard::AuthorizationGuardDefinitions,
     user::models::{Role::Administrator, User},
 };
 
 pub type FormId = types::IntegerId<Form>;
 
-#[async_trait]
-impl<Repo: FormRepository + Sized + Sync> Resolver<Form, Error, Repo> for FormId {
-    async fn resolve(&self, repo: &Repo) -> Result<Option<Form>, Error> {
-        repo.get(self.to_owned()).await
-    }
-}
-
 #[derive(Deserialize, Debug)]
 pub struct OffsetAndLimit {
     #[serde(default)]
@@ -218,13 +208,6 @@ impl DefaultAnswerTitle {
 
 pub type AnswerId = types::IntegerId<FormAnswer>;
 
-#[async_trait]
-impl<Repo: FormRepository + Sized + Sync> Resolver<FormAnswer, Error, Repo> for AnswerId {
-    async fn resolve(&self, repo: &Repo) -> Result<Option<FormAnswer>, Error> {
-        repo.get_answers(self.to_owned()).await
-    }
-}
-
 #[derive(Serialize, Deserialize, PartialEq, Debug)]
 pub struct FormAnswer {
     pub id: AnswerId,
diff --git a/server/infra/resource/src/repository/form_repository_impl.rs b/server/infra/resource/src/repository/form_repository_impl.rs
index 1096ef0b..06f26b45 100644
--- a/server/infra/resource/src/repository/form_repository_impl.rs
+++ b/server/infra/resource/src/repository/form_repository_impl.rs
@@ -12,7 +12,6 @@ use domain::{
 use errors::{domain::DomainError, infra::InfraError::AnswerNotFount, Error};
 use futures::{stream, stream::StreamExt};
 use outgoing::form_outgoing;
-use types::Resolver;
 
 use crate::{
     database::components::{DatabaseComponents, FormDatabase},
@@ -303,7 +302,7 @@ impl<Client: DatabaseComponents + 'static> FormRepository for Repository<Client>
     }
 
     async fn post_comment(&self, answer_id: AnswerId, comment: &Comment) -> Result<(), Error> {
-        let posted_answers = answer_id.resolve(self).await?.ok_or(AnswerNotFount {
+        let posted_answers = self.get_answers(answer_id).await?.ok_or(AnswerNotFount {
             id: answer_id.into_inner(),
         })?;
 
diff --git a/server/types/src/lib.rs b/server/types/src/lib.rs
index 1feca007..45ee6227 100644
--- a/server/types/src/lib.rs
+++ b/server/types/src/lib.rs
@@ -1,4 +1,3 @@
-use async_trait::async_trait;
 #[cfg(feature = "arbitrary")]
 use common::test_utils::arbitrary_uuid_v7;
 use deriving_via::DerivingVia;
@@ -36,8 +35,3 @@ impl<T> Id<T> {
         Self(Uuid::now_v7(), std::marker::PhantomData)
     }
 }
-
-#[async_trait]
-pub trait Resolver<T, Error, Repo> {
-    async fn resolve(&self, repo: &Repo) -> Result<Option<T>, Error>;
-}
diff --git a/server/usecase/src/form.rs b/server/usecase/src/form.rs
index 888a6bb7..2ecaac6d 100644
--- a/server/usecase/src/form.rs
+++ b/server/usecase/src/form.rs
@@ -26,7 +26,6 @@ use futures::{
     future::{join_all, OptionFuture},
     stream, try_join, StreamExt,
 };
-use types::Resolver;
 
 use crate::dto::AnswerDto;
 
@@ -146,23 +145,22 @@ impl<R1: FormRepository, R2: NotificationRepository> FormUseCase<'_, R1, R2> {
         title: DefaultAnswerTitle,
         answers: Vec<FormAnswerContent>,
     ) -> Result<(), Error> {
-        let is_within_period = form_id
-            .resolve(self.form_repository)
-            .await?
-            .and_then(|form| {
-                let response_period = form.settings.response_period;
-
-                response_period
-                    .start_at
-                    .zip(response_period.end_at)
-                    .map(|(start_at, end_at)| {
-                        let now = Utc::now();
-                        now >= start_at && now <= end_at
-                    })
-            })
-            // Note: Noneの場合はフォームが存在していないかそもそも回答期間が無いフォーム
-            .unwrap_or(true);
-
+        let is_within_period =
+            self.form_repository
+                .get(form_id)
+                .await?
+                .and_then(|form| {
+                    let response_period = form.settings.response_period;
+
+                    response_period.start_at.zip(response_period.end_at).map(
+                        |(start_at, end_at)| {
+                            let now = Utc::now();
+                            now >= start_at && now <= end_at
+                        },
+                    )
+                })
+                // Note: Noneの場合はフォームが存在していないかそもそも回答期間が無いフォーム
+                .unwrap_or(true);
         if is_within_period {
             self.form_repository
                 .post_answer(user, form_id, title, answers)
@@ -276,14 +274,15 @@ impl<R1: FormRepository, R2: NotificationRepository> FormUseCase<'_, R1, R2> {
         let can_post_comment = match comment.commented_by.role {
             Administrator => true,
             StandardUser => {
-                let answer = answer_id
-                    .resolve(self.form_repository)
+                let answer = self
+                    .form_repository
+                    .get_answers(answer_id)
                     .await?
                     .ok_or(AnswerNotFound)?;
 
-                let form = answer
-                    .form_id
-                    .resolve(self.form_repository)
+                let form = self
+                    .form_repository
+                    .get(answer.form_id)
                     .await?
                     .ok_or(FormNotFound)?;