A de-aged Eruri AU in which Levi, a 32 year old man who runs a restaurant, helps to raise Erwin, the young neighbor's son, and when Erwin is 22 he --- oh, excuse me.
*listens in headphones*
Is that so? I see, I see.
*clears throat*
Apologies. Apparently this isn't a SnK doujinshi.
Aioi Musubi