@Mai_loves_icecream what @Short_Circut said. I don't know what they're doing with Pixiv, but there are definitely seven volumes, and the seventh volume contains up to chapter 55 plus an epilogue.
@Nulll I think what's going on is that Uta did not immediately lose her memories again in Ryuu +...
@remiska Yeah. There are only 55 chapters, so the pairs are getting 13-14 chapters each, and this is chapter 11. It's now or never for the big drama and/or reveal in each storyline.