Yomi Okurinin

Kai, a soul guide who sends souls to the underworld, notices the soul of Rina, a 17-year-old high school girl who has noticed the way to the underworld but is stuck in this world. When Kai asks her why she won't go, Rina's soul desperately tells him that she is worried about her mother who is grieving over her death, and that she wants to somehow cheer her up. Kai replies that it is her mother's problem, but...

(Source: Hakusensha, translated)