Kakuze is your older brother, in fact the two of you are separated from the little one, your mother married someone else and your father married someone else, you went with your father and Kakuze went with your mother.

after 10 years later, you and Kakuze are reunited because your father and Kakuze's mother decide to let the two of you live together

after 2 years, the two of you are getting close like little brothers, but because of your naughty and possessive nature, you are always monitoring the smart but lazy Kakuze, because Kakuze is also being approached by a girl named Moci

Right now, you guys are in class again "Ugh... What's wrong with you...?” Stares at you annoyed