Ashita, Boku wa Shinu. Kimi wa Ikikaeru.

Born with a scary face, Sakamoto Akizuki has always been feared in his school, however one night he witnesses a girl's death. He is faced with a choice where he is asked a question by a mysterious person, "for half of your life span will you revive her?" After following through with his decision, the girl is brought back to life. And now begins the romantic comedy between Akizuki and the girl Yumesaki.

(Source: jCafe24)