Elderly couple Yumi and Aiko Mahou run the best onsen in Granite Falls. Customers travel from all over the world to experience the exquisite quality of the water. So warm, so rejuvenating, so...natural? While Yumi and Aiko claim their onsen rests on a natural well, some have come to suspect that the source of the excellent water may be otherworldly. After all, it's too perfect, too (dare they say) magical? What secrets are the Mahous hiding beneath their onsen? #DecemberSimsieShell #onsen