Yusa Kurobane

Yusa is a first-year student and the vocalist for the band How-Low-Hello. She is able to speak to the dead. She uncontrollably channels her dead older sister Misa, who occasionally possesses her. When this occurs, her appearance changes, such as her eye color turning from blue to red.

Misa lets Yuu plunder her abilities after hearing his plan from Nao. Before that she had written a letter to Yusa, after her ability is taken she reads it and starts crying knowing that she was with her and everyone the whole time. She no longer possesses any powers.
(Source: Crunchyroll)