debut chapter: 64

recent chapter: 64

current age: unknown

affiliation: krieg pirates

Yuki has a key around his neck as a kid which means he'd been living his childhood life as a "kagikko" (鍵っ子).

"Kagikko" literally means "key kid" or "latchkey kid". In Japan it's common for a child (usually a single child) to come home to an empty house due to their parents working, so a child would spend the rest of his/her day alone until the parents return from work- usually late in the afternoon or at the evening. I'm assuming that the reason the house key is hung around a child's neck is to make the child aware of where the key is- so it won't get lost, because young children could be careless most of the time- and the other reason is to make their teachers aware of their students' situation, so that when there's a problem the teachers would know what to do. Probably it's also to make the neighborhood aware of the child's situation too.

      Never having appeared in the anime, Kagikko is a Krieg Pirate who wears a key on his head. Literally nothing else is known about him.

debut chapter: 64

recent chapter: 64

current age: unknown

affiliation: krieg pirates