Everything he's ever done, he's done for him.

When they were younger, he protected him from bullies – backed him up when he needed it. Scared away those who threatened him. Because he was fragile. Himchan was always a little bit weaker. Yongguk had realized this and made sure he was always strong enough to fend for his friend. To be able to look mean enough to scare away those who threatened him or tried to harm him. Yongguk made sure – that Himchan was okay; safe – and happy.