"Ahhh..." Makoto, a university student living at his brother's wife's house, is still unable to recover from the shock of being rejected by his beloved girlfriend. Then, unable to see her, her sister-in-law Sayuri called out to cheer up Makoto. "Look, this will cheer you up... you can massage it as much as you like." "...Eh?!" Her sister-in-law reveals her breasts and forces her to have a fight. Makoto can't contain her excitement as she faces her step-sister's beautiful big breasts, which are incomparable to her ex-girlfriend. One night, when my brother was away on a business trip.