Mima Ryousuke

Haruka's older brother, Mima Ryousuke works as a Minmes operator at Building B. After learning of the inhumane nature of the organization, Haruka tried to persuade Ryousuke to forsake his work but failed.

Spoiler

Later on, he offered Ikumi to help them escape and gave her his access card but was caught later on. Ultimately he was killed in front of Haruka who was trying to save him.