God damnit I was about to think "well maybe he don't want to die, maybe he finally decided to live an happy life with his cute yandere gf" but of course not...
Judging from how another manga just ended, he'll fall for her, they will honestly start dating near the end and in the last story chapter she'll stab him for a zany reason.
@Nakanowatari: Naughty Succubus "Saki-chan" A "pure" 4-koma comedy, but in the end it might or might not have been "Game Over" for the MMC, as FMC is a succubus after all.