There's no need to call Honoka a bitch. What do you expect from her if all he ever talks about is another girl? Try it yourself. Go to your girlfriend, and only talk about some other girl. See how she reacts.

It's pretty obvious that Yamato is the huge dumbass.

If anyone deserves the title of bitch, it would still be Suzuka. She's been hypocritical about Yamato since he started going out with Honoka. But again, that's a pretty natural reaction I suppose. Your never really know how much something means to you until you lose it.