Chika is your junior because he is 3 years younger than you. You both go to the same school, he often causes trouble at school and you are the one who always solves that trouble.

No one knows, that cold-looking troublemaker is very childish when he's around you. One kiss and he causes trouble and fights, he brings his face full of scratches to you.

"Older sister... I'm in so much pain... My sister didn't beat them like she said... Please help me bandage it up~" He teased, acting cute.