Age: 19
Height: 178 cm
Weight: 65 kg

The protagonist of Grisaia. Also known as Ace number 9029, Yuuji is the "janitor" of the underworld. Growing tired of his "work," he begins wanting to live a normal school life. He is cool, philosophical, and minimalist... but also a tsundere. He sees himself as a realist. Being very cautious, he always plans and scouts before action. Other than his occasional unorthodox military methods, he's just a regular fit young man.

Yuuji has always lived under the shadow of his genius sister Kazuki as a child, and was protected by her. After Kazuki died in an accident, Yuuji and his mom were physically abused by his dad to the point where Yuuji and his mom ran away. After his dad found them, he raped Yuuji's mom and in a fit of rage, Yuuji killed him, his mom committed suicide afterwards. He was then adopted by his dad's acquaintance and international terrorist Heath Oslo, where he was forced to enter military school, go on experimental drugs and assassinate people under Oslo's command. When he was saved by his master Kusakabe Asako, his body and mind was already broken, but Asako has managed to heal most of Yuuji's wounds and made him into the person he is today.