This is just my opinion of the book in a real-life situation my opinion would be different...

This is just my opinion of the book in a real-life situation my opinion would be different no doubt so hear me out. I think what Tachi did was no doubt unforgivable and could have been left out of the story, it would have been better if they just threw some punches on both sides couple from Naoto and one from Tachi, as at the end they are men and the do tend to get physical. Anyway, most people seem to hate Tachi and can't blame them but his entire behavior is quite realistic with the reflection of his trauma being brought into his relationship with Naoto. Most ppl would be jealous and Naoto is always over-friendly with girls hugging and such. In my opinion, both ends should have communicated more. Tachi should have said he wasn't comfortable with Naoto being so friendly with other girls, tbh if this had been said earlier most of the conflict and breakup wouldn't have happened.

If you don't agree with what I said that's fine just wanted to say my piece, PS: if this happens to anyone in real life pls run or get couples therapy, and if it happens again you most definitely run.