Aina is a human toilet instructor who accepts requests from S women across the country for toilet modification training. Her program is considered extremely rigorous, even by masochistic men. For her, toilet modification is not merely a job—it's also a personal passion. Her goal is to create a comprehensive-type toilet capable of accepting all forms of waste, including feces, urine, phlegm, vomit, and vaginal discharge. She embodies the role of a human excretion machine, exuding the majesty of a queen of filth. With the ultimate objective of achieving complete consumption of golden excrement, her training relentlessly drives toward this end.