Gasai has Hinata at knifepoint. She's far more concerned that she will steal Amano than about the current situation.
Amano makes her back down with the only thing he has to offer: officially acknowledging her as his girlfriend.
Fourth finds Tenth and kills him.
We get a flashback of Ninth's backstory.
Akise sets Amano and Gasai up on a date. Would Amano fall for Gasai if he didn't know about the bodies?
Akise snoops around. But Gasai has disposed of the bodies.
Fourth sets Amano and Gasai up to take the fall for Tenth's murder.