So Yachie's nickname shall be...

Rumia, what's got you troubled?

Well, um... I'm trying to think of nicknames for the new girls.

Ei-chan,

Uu-chan,

Kuu-chan.

That's what I've got so far.

The way this is going, I wonder if she'll call me "Yacchan"...

Naturally what you'd call a yakuza. Yacchan (やっちゃん) is a gentle, colloquial way of referring to the yakuza.

Call me what you want...

She really liked it.