Uh oh, stalker alert?
I'd say an admirer from her volleyball days, probably a junior or something of the sort.
Is the implication is that she gave up on the club because she’d rather just see Takamie after school everyday?
I think it was an already dead non-club, and she decided to finally let it go, or something along those lines.
In any case, cute! Great chapter. I absolutely love seeing Takamine grow as a character and person and see her outlook on practically everything change and especially love all the cute moments between her and Sakura. Bathe me in this shit, dude. I assume the new mystery girl is some sort of a "fan" from the volleyball stuff, not too concerned about her. I'm more interested in what Sakura was so morose about, we don't see much from her perspective, and I hope we do at some point.