Sumire and Mai were introverted and unnoticeable in class, but their sensitive nipples were discovered by bullies who mocked them daily. When they finally consulted their homeroom teacher, the teacher suggested "nipple condition improvement" as a reason for an unexpected double nipple development! Despite their plain appearances, their nipples would perk up at any moment. They need to get used to various stimuli... (laughs) Close friends can lick each other's nipples... use toys during tests... The repeated nipple development caused both of them to lose control! Convulse!! Double nipple orgasm!!!
