Juujirou Oni  

The Gatekeeper from Hell, 鬼 十次郎

This individual behaves as if he is an older brother at the camp, although he himself is a first-stringer. He chooses to remain on the fifth court because his goal is to elevate all other courts, even though his actual skill level places him higher. In the U-17 camp, Oni can be found on the fifth court alongside Irie Kanata, who also finds themselves in lower courts than their true abilities. Despite being placed on the fifth court, members of the first court recognize the power of both Oni and Irie, who are actually from the third court. During the shuffle matches in the U-17 camp, the fifth court emerges victorious over the third court due to Irie feigning injury and unable to play. As a result, Oni is now considered a member of the third court.