(Maybe my sister-in-law is trying to seduce me?) Takuya's pregnant wife has returned to her hometown, and he is enjoying living alone for the first time in a long time. Then, his sister-in-law Yuka suddenly comes to help with the housework, but... She frequently flashes her breasts and panties, and while he is confused by Yuka's strangely sexy appeal, his cock gets hard. Furthermore, when Yuka sees this, she says, "I'll let you release some of that energy so you don't cheat on me."