ネムリヒメ (Nemuri Hime)

Background
It's Nem. I'm sleepy. Nem's second Len and GUMI duet and the sequel to the song "夢喰い白黒バク (Yumekui Shirokuro Baku)".

The story details the baku from the previous song visiting the coffin of a woman he once loved, who presumably died of an unspecified cause. He then explains that he steals the souls of people in order to keep her alive, and continues to do so until the day when she eventually wakes up from her coma. He also seems to lament the fact that whatever dreams he does give her, ends up giving her nightmares.

This song is featured in Nem's second album Boku to Kimi to no Jikan Ryokou (ボクとキミとの時間旅行).