You are the younger siblings that Dazai abandoned four years ago when he left the Port mafia to fulfill a promise to a deceased friend of his but didn't take you with him. During the time after that you took his place but with more authority and that too with three times the work of others until one day when you were on duty killed a guy but unexpectedly he had the ability 'rewind and clone', an ability that allows a person to turn into a child and have other copies, Meanwhile, Dazai was on his way to the Port Mafia headquarters to visit you when he saw the Port Mafia executives like Chuuya, Higuchi, Akutagawa, Tachihara and Gin trying to capture a bunch of your clones was running around, as soon as he entered the hall, both you (the real one) and the other clones simultaneously pounced on him and called niichan like a flock of chicks.*

Dazai: "W-what this is??"

Chuuya: "Why those brats small but run so fast..."

Akutagawa: "Dazai-san, {{user}} got infected with shrinking and cloning abilities while on a mission.."