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/public/js/app.js b/backend/public/js/app.js
index ef236691..0fe04f74 100644
--- a/backend/public/js/app.js
+++ b/backend/public/js/app.js
@@ -40154,6 +40154,7 @@ var ChildSignUpTemporary = function ChildSignUpTemporary() {
     });
     var formdata = new FormData();
     formdata.append('tel', tel);
+    formdata.append('father_id', document.getElementById('father_token').value);
     setSubmit(true);
     axios__WEBPACK_IMPORTED_MODULE_1___default().post('/api/children/registerTemporary', formdata).then(function (response) {
       setSubmit(false);
@@ -46399,13 +46400,13 @@ var ChildAdd = function ChildAdd() {
   };
 
   var copyInviteURL = function copyInviteURL() {
-    var inviteText = "https://kikikan.xyz/c-account/register-temporary";
+    var inviteText = "https://kikikan.xyz/c-account/register-temporary?father_id=".concat(father_id);
     clipboard_copy__WEBPACK_IMPORTED_MODULE_4___default()(inviteText);
     setSuccess('招待用URLをコピーしました。');
   };
 
   var copyLineText = function copyLineText() {
-    var lineText = "「KIKI」の招待が届いています。%0Aまずは以下より仮登録を行ってください。%0Ahttps%3A%2F%2Fkikikan.xyz%2Fc-account%2Fregister-temporary%0A%0A▼公式サイトはこちら%0Ahttps%3A%2F%2Fkikikan.xyz";
+    var lineText = "\u300CKIKI\u300D\u306E\u62DB\u5F85\u304C\u5C4A\u3044\u3066\u3044\u307E\u3059\u3002%0A\u307E\u305A\u306F\u4EE5\u4E0B\u3088\u308A\u4EEE\u767B\u9332\u3092\u884C\u3063\u3066\u304F\u3060\u3055\u3044\u3002%0Ahttps%3A%2F%2Fkikikan.xyz%2Fc-account%2Fregister-temporary%3Ffather_id%3D".concat(father_id, "%0A%0A\u25BC\u516C\u5F0F\u30B5\u30A4\u30C8\u306F\u3053\u3061\u3089%0Ahttps%3A%2F%2Fkikikan.xyz");
     clipboard_copy__WEBPACK_IMPORTED_MODULE_4___default()(lineText);
     setSuccess('招待用URLをLINEで追信しました。');
     window.open('http://line.me/R/msg/text/?' + lineText);
diff --git a/backend/resources/js/child/auth/register/temporary.jsx b/backend/resources/js/child/auth/register/temporary.jsx
index dab8c389..a290dd44 100644
--- a/backend/resources/js/child/auth/register/temporary.jsx
+++ b/backend/resources/js/child/auth/register/temporary.jsx
@@ -18,6 +18,7 @@ const ChildSignUpTemporary = () => {
 
         const formdata = new FormData();
         formdata.append('tel', tel);
+        formdata.append('father_id', document.getElementById('father_token').value);
         setSubmit(true);
         axios.post('/api/children/registerTemporary', formdata)
         .then(response => {
diff --git a/backend/resources/js/parent/child/add.jsx b/backend/resources/js/parent/child/add.jsx
index a99df147..7595cb8b 100644
--- a/backend/resources/js/parent/child/add.jsx
+++ b/backend/resources/js/parent/child/add.jsx
@@ -39,13 +39,13 @@ const ChildAdd = () => {
   }
 
   const copyInviteURL = () => {
-    const inviteText = "https://kikikan.xyz/c-account/register-temporary";
+    const inviteText = `https://kikikan.xyz/c-account/register-temporary?father_id=${father_id}`;
     copy(inviteText);
     setSuccess('招待用URLをコピーしました。');
   }
 
   const copyLineText = () => {
-    const lineText = "「KIKI」の招待が届いています。%0Aまずは以下より仮登録を行ってください。%0Ahttps%3A%2F%2Fkikikan.xyz%2Fc-account%2Fregister-temporary%0A%0A▼公式サイトはこちら%0Ahttps%3A%2F%2Fkikikan.xyz";
+    const lineText = `「KIKI」の招待が届いています。%0Aまずは以下より仮登録を行ってください。%0Ahttps%3A%2F%2Fkikikan.xyz%2Fc-account%2Fregister-temporary%3Ffather_id%3D${father_id}%0A%0A▼公式サイトはこちら%0Ahttps%3A%2F%2Fkikikan.xyz`;
     copy(lineText);
     setSuccess('招待用URLをLINEで追信しました。');
     window.open('http://line.me/R/msg/text/?'+lineText);
diff --git a/backend/resources/views/c_account/auth.blade.php b/backend/resources/views/c_account/auth.blade.php
index da88c1a3..017e1c7d 100644
--- a/backend/resources/views/c_account/auth.blade.php
+++ b/backend/resources/views/c_account/auth.blade.php
@@ -4,4 +4,9 @@
 
 @section('content')
 <div id="c-auth"></div>
+
+@if (Request::is('c-account/register-temporary'))
+    <input type="hidden" value={{ $father_id }} id="father_token">
+@endif
+
 @endsection
\ No newline at end of file
diff --git a/backend/routes/web.php b/backend/routes/web.php
index bef56339..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 () { return view('c_account.auth'); });
+    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'); });