I thought the Hanabi came across as a bit manipulative in the first chapter, when she started saying what she did to cheer Konomi up. Yes, it's good to cheer her up, but she sounded like she was just saying what she thought Konomi wanted to hear.
Also, I don't see why people are calling her the typical "clueless" MC. She seems pretty aware of the sexual implications, though perhaps still uncertain of her own sexuality. She's not having the "we're girls so that's completely wrong" reaction, but she's not obviously embracing it either. We haven't really gotten her thoughts on her own sexuality yet, so for now I kind of feel like she might only just be discovering it, or perhaps has been avoiding these revelations.
Anyway, it's completely unexpected for me, but I like Hanabi-Yuu. The drunk is usually the character I like but don't consider seriously, but I like Yuu so far.. She's holding second place just above Konomi, while Iori holds a decent lead as my first choice. That "Hanabi loves me?" made my heart skip a beat. Depending on which direction this is taken, I'll probably either love or hate it.