Yui, the daughter of a human woman and an Arume, is a prominent member of the resistance in Japan in 3027, firmly opposing the Arume's millenium-long colonial occupation and the imposition of their values upon humanity. As a child, a girl that she loved was killed after being selected for the military's anti-Thought Condensing Weapon program, and as a result she feels especially strongly about rescuing those given the neutralization vaccines from their fates. Yui has a weakness for cute girls, and usually has very little regard for their personal boundaries.
Voiced by [Nazuka Kaori](https://anilist.co/staff/95078/) in the radio drama adaptation of BLUE DROP.