The stake (Pixiv Fanbox)

Stakes are perfect tools to teach impertinent trainees a lesson of endurance and give them some time for reconsideration. The trainees’ hands are locked in place at a stake coming from the ground. The height of the stake is too low to comfortably stand or squat but also too high to comfortably sit, forcing the trainees to wiggle around while trying to find a somewhat bearable position. This is also great for use outside or in public places, as the trainees barely have any meaningful way to cover themselves using their legs without over-exhausting themselves. Additionally, it’s always fun to add some big and uncomfortable toys, making them slowly go insane from pleasure while trying to find a resting position. Just image a helpless trainee amidst a crowd of curious bystanders, only being able to wiggle and cum until they pass out from exhaustion~