Kozaru

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

Appearance
Kitsunesaru dons a typical ninja outfit, with a large green scarf, a purple sash around his waist, and arm bracers. He also has some sort of headgear on his face.

Fallen Guardian arc
Yuta and Kitsunesaru accompany Rieze to the Akiba 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, Yuzuko, and Kushi Yatama, Kitsunesaru is one of the five representatives from D.D.D. participating in the Shibuya raid. When Shiroe begins panicking, causing the raid party to be in disarray, Kitsunesaru comments on the sloppiness of the whole thing.

D.D.D Diaries
Kitsunesaru is one of the D.D.D members that originated from D.D.D Diaries, a Japanese Log Horizon fan fic (and the source for most of D.D.D's members).