Susumu and Yui's only son, Katsuhiko, needed a huge amount of money to undergo surgery. A wealthy person named Sonoda will pay the full cost of Katsuhiko's surgery, depending on the conditions, so Susumu and Yui go to meet Sonoda in person. Sonoda has presented a ridiculous condition to the two, "I want to hire Yui as a meat urinal for a year." Susumu strongly opposed it, but Yui gave in to her strong desire to help Katsuhiko and signed her slave contract.
