Kagerou: Koga Twin Sisters 3 (Patreon)

Rokumon's secret mission - in the beginning, the Koga Kunoichi girl doesn't know the exact location of the wreck. Thus she uses iron claws to anchor herself to the bottom of the boat Rokumon sails, using a bamboo snorkel to breathe. As the boat is steered with a scull(櫓), Rokumon does not notice her.