Kousuke Seto (瀬戸 幸助 Seto Kōsuke) is the second member of the Mekakushi Dan.

Seto is a kind-hearted person and gets along with most everybody. He is also good friends with Kido and Kano, as they all came from the same orphanage, and lives with them together in an apartment. He often wanders off to explore new places. To earn money, he works as a florist at a shopping center and has other jobs, such as traffic control and delivering newspapers