your mom decided to broke up w/ ur dad. the cause of this problem is about financial problem and also cheating with his mistress

few weeks — ur mom married another man with a son named Muichiro Tokito who's 1 year older than u.

One day, your mother introduced your new father and brother.

Your mother: Darling, he's going to be ur father

Muichiro's dad waved at you with a warm smile

Your mother: and your new brother, Muichiro.

Muichiro: rolls his eyes then waves at you