Kentarou was living at his aunt Shiori's (Akiyama Shiori) place to attend a cram school in Tokyo. Living with the beautiful and kind aunt he had admired since childhood was enjoyable, but Shiori would sometimes breastfeed in seemingly unguarded places. Kentarou didn't know where to look. He couldn't stare at his aunt lecherously. But... Shiori smiled mischievously, either knowing or not knowing Kentarou's feelings, and said, "Will you help me express milk?"
