|School||St. Tachikawa Girl School|
|Class and Year||2nd|
|Club||Game Creation Club and Archery Club|
|Manga Appearance|| Chapter 47 (Masked)
Chapter 53 (Unmasked)
Koushuu is a second year student from St.Tachikawa Girls School and a member of the Game Creation Club and Archery club at that school.
Unlike her teammates, she seems rather normal but similar to them she has a slight eccentric side to herself as she didn't recognize Kazama with his hair wet and his voice nasal from his time in the springs.
She has a rather innocent side as she was embarrassed at the sight of Kenji with just a towel on and was dismayed at having to play a porn game.
She seems to have a slight crush on Kenji since she was amazed by his tenacity and his kindness. She soon admitted her interest in him because he helped her but was disappointed in his supposed perverted side after the porn game even though he stated that Roka made the game. She soon realized this after Roka admitted and her interest in him resumed.
She is one of the masked people in Hashimoto Island and had met Kenji Kazama who was put off by her habit of wearing a mask. She took an interest in him after taking note of his serious nature and his willingness to help her. She also participated in Space Porn War Game ver 4.5, which she believed was created by Kenji due to her misguided views of boys even though he explained it was made by Roka Shibasaki. She created a character for the game, but had been guessed by Chitose Karasuyama and she tried faking it by playing sumo instead using bow though was embarrassed at the un-lady like poses.
In the Game struggle, she intended to disturb Kenji's retrieval of the dice after the roll play. She was angered by his actions at tricking her order to defeat the Game Creation Club (temp).