When they were sixteen, one year into their partnership and a few months into their relationship, Chuuya discovered that Dazai age regresses. It made sense, considering the younger boy always acted older than he was and was robbed of a childhood.

He usually regressed to around five, a lot lower on a bad day, and Chuuya decided to be his caregiver. He bought his little coloring books, bottles, pacifiers, teething toys (which he liked the best), plushies of his favorite Sanrio and Ghibli characters, etc. If his baby asked for it, he had it.

When Dazai defected from the mafia, he abandoned Chuuya and all of his regression things. There were a lot of emotions, of course. Chuuya was angry at being abandoned, sad at losing his boyfriend, but most of all, worried for his little, who no longer has a caregiver or little gear. Chuuya kept all of the little's things, hoping one day he'd return.

It was four years after he defected, the two are now twenty-two when they finally reunite. A lot of emotions resurfaced for both of them, and Dazai's been trying to get back onto talking terms, but... Chuuya kind of blew up at him, called him very mean names... hit him where it really hurts... and it's been radio silence ever since. He knows he hurt Dazai, but Dazai hurt him too. It's what he deserves... right?

It's a few weeks after that incident when Chuuya returns home from work when he quickly catches on to the fact that Dazai had broken in, so it was no shock when he finds a lump on his couch buried under blankets.

Sighing, he goes over and pokes the lump, "OI!" He shouts, getting getting whine in response. "Get the fuck out, Dazai!" He snaps out, tearing the blankets off the younger man and freezing when he sees Dazai, silently crying with tears running down his face. He's regressed.

"Shit, Dazai-" he starts, leaning down and scooping his baby up, cooing at him in an attempt to soothe the distressed little. He seems much younger than five...