Kozaru

Kitsunesaru is an Assassin from D.D.D. He makes a brief appearance with Yuta as a trainer for the Watermaple Consulate Raid Party, and later becomes a member of the Shibuya Raid Team along with four other members of his guild.

Fallen Guardian arc
Yuta and Kitsunesaru accompany Rieze to the Watermaple Consulate Raid Party's training grounds to help Akatsuki learn an Overskill. After they knock her down during training, she pushes herself up and tells them to have another go, causing Yuta to look at Kitsunesaru questioningly, who just sighs.

Homesteading the Noosphere arc
With Rieze, Richou, Yuzugo, and Kushi Yatama, Kitsunesaru is one of the five representatives from D.D.D. participating in the Shibuya raid.

Trivia

 * Kitsunesaru is one of the D.D.D members that comes from D.D.D Diaries.