Ushio Kofune

Ushio is the deuteragonist of the series. She is the daughter of Alan, sister of Mio, and adoptive sister of Shinpei.

[Spoiler] Ushio holds feelings for her childhood friend, and adoptive brother, Shinpei. [/Spoiler]

[Spoiler] In the original timeline, Ushio was strangled to death when she tried to save Shiori from Shiori's shadow, together with Ushio's own shadow. [/Spoiler]

(Source: MANGA Plus)