@Hejti
There's 3 ways it can go:
1. Chiaki dies in the explosion (Unlikely, Bad End trope)
2. Chiaki is critically injured, the JMT deny their association with him, he joins Ms. Jelly as a "mutant" or whatever they're called in this series, I can't remember.
3. Chiaki emerges mostly unscathed, swears vengeance against Ms. Jelly for trying to kill him, and the rest of the manga is him and the Hero Harem hunting her down. A the end, the main hero bitch disobeys orders and kills Ms. Jelly.
There's no good end for the Chiaki/Ms. Jelly relationship, she's too far gone. I mean, she's blowing up a goddamn building because her manuscript was rejected...
Don't get me wrong, Chiaki's at fault, too. Only an absolute retard would think whipping his dick out in a bar (that his girlfriend often goes to) is a good way to prove to a psychopath that he hasn't had sex with her. He shouldn't gotten involved with the dumb bimbo in the first place.