San-Daime is the engineer and damage control officer for the pirate vessel Bentenmaru, tasked with maintaining its propulsion systems and managing repairs during operations. He maintains a persistently pessimistic demeanor, habitually expecting the worst outcomes—especially concerning the ship's new and relatively inexperienced captain. This wariness translates to visible anxiety over potential damage to the Bentenmaru, particularly when external groups like the school space yacht club engage with the vessel, as he fears their actions might jeopardize its structural integrity. Off-duty, he collects stuffed teddy bears. His appearance features dark green hair and violet eyes.