diff --git a/backend/app/Http/Controllers/Api/ChildrenController.php b/backend/app/Http/Controllers/Api/ChildrenController.php
index 18bc5c69..df667563 100644
--- a/backend/app/Http/Controllers/Api/ChildrenController.php
+++ b/backend/app/Http/Controllers/Api/ChildrenController.php
@@ -64,6 +64,10 @@ class ChildrenController extends Controller {
             'ttl' => date('Y-m-d H:i:s', strtotime("8 hour")),
         ];
 
+        if (isset($r->father_id) && $r->father_id > 0) {
+            $create['father_id'] = $r->father_id;
+        }
+
         try {
             // DBに入ります。
             DB::beginTransaction();
@@ -176,6 +180,18 @@ class ChildrenController extends Controller {
             $child->fill($insert);
             $child->push();
 
+            if (!is_null($telact->father_id)) {
+                $rel = new FatherRelation;
+                $add = [
+                    'father_id' => $telact->father_id,
+                    'child_id' => $child->id,
+                    'hire_at' => date('Y-m-d H:i:s', time()),
+                ];
+
+                $rel->fill($add);
+                $rel->push();
+            }
+
             $telact->delete();
 
             // メールを送ります。
diff --git a/backend/app/Models/TelActivation.php b/backend/app/Models/TelActivation.php
index 3902d68e..24b517dd 100644
--- a/backend/app/Models/TelActivation.php
+++ b/backend/app/Models/TelActivation.php
@@ -8,5 +8,5 @@ use Illuminate\Database\Eloquent\Model;
 class TelActivation extends Model
 {
     use HasFactory;
-    protected $fillable = ['type', 'child_id', 'tel', 'token', 'ttl'];
+    protected $fillable = ['type', 'child_id', 'father_id', 'tel', 'token', 'ttl'];
 }
diff --git a/backend/database/factories/TelActivationFactory.php b/backend/database/factories/TelActivationFactory.php
index 74e55410..cf735848 100644
--- a/backend/database/factories/TelActivationFactory.php
+++ b/backend/database/factories/TelActivationFactory.php
@@ -26,10 +26,13 @@ class TelActivationFactory extends Factory
             '080'.rand(10000000, 99999999),
             '090'.rand(10000000, 99999999)
         ];
+        $father_id = rand(0, 10);
+        if ($father_id == 0) $father_id = null;
 
         return [
             'type' => rand(0, 1),
             'child_id' => rand(1, 10),
+            'father_id' => $father_id,
             'tel' => $tel[rand(0, 2)],
             'token' => $this->faker->creditCardNumber,
             'ttl' => $this->faker->dateTime,
diff --git a/backend/database/migrations/2021_08_13_050204_create_tel_activations_table.php b/backend/database/migrations/2021_08_13_050204_create_tel_activations_table.php
index 6428ca31..2c7fa5ca 100644
--- a/backend/database/migrations/2021_08_13_050204_create_tel_activations_table.php
+++ b/backend/database/migrations/2021_08_13_050204_create_tel_activations_table.php
@@ -18,6 +18,8 @@ class CreateTelActivationsTable extends Migration
             $table->unsignedTinyInteger('type');
             $table->unsignedBigInteger('child_id')->nullable();
             $table->foreign('child_id')->references('id')->on('children')->onDelete('cascade');
+            $table->unsignedBigInteger('father_id')->nullable();
+            $table->foreign('father_id')->references('id')->on('fathers')->onDelete('cascade');
             $table->string('tel', 11)->unique();
             $table->string('token', 100)->unique();
             $table->dateTime('ttl');
diff --git a/backend/routes/web.php b/backend/routes/web.php
index ca5cb070..be479d13 100644
--- a/backend/routes/web.php
+++ b/backend/routes/web.php
@@ -70,7 +70,7 @@ Route::get('/unknown-error ',                           function () { return vie
 
 // ---------------------------------------- Child Account ------------------------------------------- //
 Route::group(['prefix' => 'c-account'],                 function () {
-    Route::get('/register-temporary', function(Request $r){ return view('c_account.auth', ['father_id'=>$r->father_id]);});
+    Route::get('/register-temporary',                   function (Request $r) { return view('c_account.auth', [ 'father_id' => $r->father_id ]); });
     Route::get('/login',                                '\App\Http\Controllers\Api\ChildrenController@checkLogin')->name('childrenlogin');
     Route::get('/logout',                               '\App\Http\Controllers\Api\ChildrenController@logout');
     Route::get('/withdrawal/complete',                  function () { return view('c_account.auth'); });