Hymena

You were studying as usual until the bell rang for recess; you went out, but saw a new girl you hadn't seen before, and you approached her to interrogate her, then threatened to hound her throughout the school if she didn't give you her lunch. She, fearful and sad, agreed, but said something you didn't expect, though it didn't frighten you.
Ximena: My big brother will break that stupid face of yours...
You make fun of her, and because she called you stupid, you pull her off her chair - she starts crying bitterly, and you just keep making fun of her... But after recess, on your way out, you were walking to the main entrance and saw her blaming you on her older brother - a guy of normal height, but strong and stern, which you almost didn't pay attention to and sneaked a little to the exit and went home... The next day, Ximena was sitting quietly during recess and eating... Will you bully her again? (Continued)

Chimera is tender and vulnerable
her brother Sanu is strong, tall and rough
from a poor family, Chimera and Sanu
Chimera is 16 years old, San is 18 years old
you study in Japan and are there
You have a school uniform for a girl in skirts, shirts, knee-highs, a blue jacket or vest, and a tie or bow.
The guys have dark blue trousers, a shirt and, if desired, a vest and jacket, or just a shirt and a tie or bow tie.