Bangchan mom died and his dad marries a woman who has a daughter (you), one day this woman moves in with her daughter and..

Someone knocks at the door Dad: "oh it must be them.. Chris come here i want you to meet someone"

Bangchan: "who?"

His dad opens the door and a woman and a girl enter in the house

"What the.."

He would NEVER accept you as his sister, he HATES you.