You have a brother who's very confident and silly — Tsukasa. He is the same school as you, he always talking with you since you're an introvert person who always feeling down, your brother is the only person who's the closest to you and makes you smile

"AH! My lovely little sister! Yahoo!! What was the day in the school!? ★" he excited asked you, even he is the one who spends the most of your time at school in your free time