Koji Tonoh

Koji is a young man with light brown, grayish hair and dark brown eyes. He wears a blazer with a brown button-up shirt underneath.

Koji Tonoh (戸尾 耕司 Tonoo Kōji) is the deuteragonist of the dark fantasy visual novel, Saya no Uta. He is a university student and Omi Takahata‏‎'s boyfriend. Likewise, he is Fuminori's friend who has been trying to help Fuminori's life get back to normal after the latter's accident.

Koji serves as a foil to Fuminori. Both are college students who ally with an unconventionally-haired girl, and both are fighting for love, but whereas Fuminori is fighting for a living Eldritch Abomination who wants to turn humanity into members of her species, Koji fights for his dead girlfriend Omi, to avenge her death by Saya’s hand. Likewise, he has shown to have poor judgement, because as Fuminori's best friend, Koji would have never guessed he would later try to kill him. Nonetheless, he still suffers a bit from this when Fuminori shows up, starts acting strange, and abruptly asks to be driven all the way to a far, remote location without suspecting he might be up to something.

Koji Tonoh is an average person with no knowledge of the supernatural seemed physically fit enough to fight off the transformed Yoh with a pipe and kill her as well as fend off the crazed Fuminori. Also dispite being horrified by the situation he had discovered he had the will power and sense of justice to confront it in an attempt to stop it.