It's a shame this has a mediocre rating, I thought it was really good. I feel like people probably saw the premise and understandably went like "ah, standard love triangle rom com with a childhood friend and a new demure girl," and then read it like it was one, where you're mostly focusing on the 'will they won't they' tug of war and who's made the most progress and such. But it's really not doing that.
When Hinaki says she doesn't like romance and she just sees Aida as a friend, in a love triangle rom-com that'd just be her being in denial, but in this one it's the truth. She's not a romantical rival with Koiwai, she really is just Aida's closest friend, and the conflict doesn't come from a love triangle but rather from the three of them having a new, important person or people in their lives and how that disrupts the dynamics they'd gotten comfortable with.
This comic is less about romance and more about that period of your adolescence where you feel like you have a good understanding of what the people you're close to are like, and what your relationships are, and that serves as a nice stable foundation for who you are. But then your friends start to change, and you meet new people, and you're changing as well. All of a sudden your world and your identity feel unstable and you have to figure yourself out all over again. I feel like this manga tells a good story about that, and I think the characters and their relationships are fun and complex if you're not just viewing it through the framework of "which girl is he gonna end up with?"