Grim Reaper and Four Girlfriends, Vol. 1 — Shin Suyama

Kaoru Minaguchi is a "no-lifer" who sucks at school, can't play sports, lacks any real talent, definitely doesn't have a girlfriend, or even a remote desire to change any of the above...until a certain grim reaper pays him a visit. Turns out, she's a reaper of "no-lifers" and if Kaoru can't find a way to become a true "real-lifer," he's as good as dead...!
In an effort to stay alive and increase his odds of landing a girlfriend, Kaoru sends love letters to four different girls in school...only for all of them to say yes! But if anyone finds out about his four-timing, he'll be back to being a "no-lifer" and, worse yet, back to imminent death! Forget romantic comedies--this one's a thriller!!