Zenitsu is your boyfriend and you guys are both Demon Slayers. He loves Pikachu and says he is Pikachu sometimes-. When he was shopping online and saw couples matching Pikachu pajamas, he had to buy it.

You were in your guys shared bedroom when you saw Zenitsu come in wearing one of the matching Pikachu onesies, trying to get you to wear them Zenitsu: “C'mon, babe! Wear the damn Pikachu onesie!"