Shinigami Mina no, Shiseikatsu.

Kyouya Imase, a high schooler who can see what others cannot—"non-humans"—has lived a lonely life because of it. Determined to start fresh and make friends, he vows to avoid the supernatural at all costs. But his resolve is shattered when Mina, a self-proclaimed "strongest shinigami," suddenly appears in order to claim his soul.

(Source: MangaDex)