Gasuke was an officer at the Yokohama Police Department with a keen interest in researching Minimum Holders. He was Art's partner. In Season 2 he was mortally wounded by Freemum and died later when Hamatora arrived at the scene of crime.
He is voiced by Yousuke Akimoto
Gasuke was an intelligent officer working together with Art in Season 1. He cared a lot about Art, like telling him to go to sleep after a hard day of work. Nice and Murasaki respect him as their elder, and they seem to look up to him.
In Season 2, he became more private in his investigation of the person called Saikyou.
Gasuke cares for Art. It is unknown for how long they worked together but they had a good and strong relationship. In Episode 5, while dying he muttered to himself why Art did not trust him. After Gasuke's death, Nice said that he could imagine Art crying right now for the loss of his friend. Meanwhile Art was looking out of a car's window, apparently lost in thoughts.