Tankoubon info

Shogakukan has a bit of info on their own site in English which I'll link to. I'll also add ISBNs, prices in yen, and new info as tankoubon come out. There are 21 tankoubon out now and an artbook.

Latest news: Vol. 21 is out!
I'll try to get a picture of the cover here. The cover picture had Yuuri and Kairu against a bluish background.

Scroll down for some pictures of the tankoubon covers