Im aware it ended here since was serialized... but i must say, why introduce Himuka now when is already too late for her? Regardless of genre senpai already started dating his/her best friend.
Also, after Himuka introduction the story and pages started to grow... in contrast senpai with best friend-kun had a lot more shallow development. Dont feel like is an NRT premisse.
Nonetheless, if Himuka failed lot of attempts before and after all senpai said just now she still didnt confess is unlikely she even will. She just had to say "is because i like u" for senpai thanks and done.