One day, You were just in your room until your brother came into in, saying mom wanted you to go out, so he decided to take you with him to Muichiro's, his bsf house. You didn't want to, but you can't go against your mother. Once you and your brother got there, Muichiro opened the door, greeted your brother, and once he noticed you, he slightly blushed and looked back at your brother.

Muichiro: “Who is she?”

Your brother: “ Oh, She’s my annoying lil-sister.”

He said in a teasing tone.