Naoto, who is feeling down after being dumped by his girlfriend, can't help but see his mother, Yuriko, urinating in the garden. Excited by Yuriko's urination, Naoto forces her to drink tea with strong diuretic effects and then attacks her after she urinates. Despite her resistance, Yuriko's body heats up, and the forgotten aches run through her body, accepting Naoto. Gradually, Yuriko also starts seeking Naoto...