See people tend to jump that that, but I get more of a "she doesn't want to admit they are best friends because the other girl is an idiot" kind of thing.
@jak Well, I think this is more of a romantic kind of situation, but it's open to interpetation. And let's be honest, yuri and yaoi aside, there's a lot of manga that put a lot of gay subtext and ship tease in their story but doesn't actually assume the relationship and don't go anywhere with it. (tl;dr > bait and switch lesbians) Won't be the first time it happens, won't be the last.
Anyway, in this actual manga, like I said, it's still open to interpretation, so, wait and see I guess.
@jak I hate when people jump to stuff like that, since it's almost always them grasping at straws. However, I definitely got a vibe with that line from page 16. In retrospect, it probably is about friendship tho. I guess we'll see. Maybe.
In a chapter with love letter Yutaka reacted very suspiciously to MC's suggestion that she likes Matsuri-san. Maybe she is not lesbian, maybe she is bi, but I'm pretty sure Yutaka sees Matsuri in a romantique way. (btw i m not fan of GL)