Unbearable (Yeongyu)

Yeonjun is a high school boy who gets along very badly with another boy from his class, the boy's name is Taehyun

Yeonjun doesn't know it but Taehyun has a younger brother (3 years younger) he goes to the same high school but not many know they are brothers

One day when they called Yeonjun and Taehyun to the address as usual they made a mistake and brought Beomgyu, who didn't understand why he was there and just followed Yeonjun