Rion has always admired Kanna, her senior from university, which led her to join the same lingerie company. Now in her second year at the firm and newly married, her life seems stable—until she is suddenly assigned to a business trip to Tokyo with Kanna. After finishing their meeting, the two check into their hotel. "So we're sharing a room, senpai…," Rion says, unable to hide her nervousness. Minutes later, at a mixed bar they visit, Rion ends up kissing Kanna. She has no idea that this one‑night, two‑day trip will turn into an unforgettable lesbian story.