Koyuki is now a wingwoman, but it looks like next chapter Haimiya-senpai is gonna get a new love rival for MC's heart
I'm thinking he will join the light music club then start spending all his time eating cake and drinking tea...Haimiya did say she wants to hear him play, so I'm thinking this might be a good way for her to look more in his direction while staying true to himself.
My concerns lie with how far Koyuki will go to help him given her methods, despite being well intentioned. Coupled with Kurose thinking that being himself is a problem, even though Haimiya already likes him for who he is.
My prediction about this new girl is that she's in this band she'll somehow get him on board to join it.