Sumire and Mai are shy and inconspicuous in class, but when their sensitive nipples are discovered, they are bullied every day. When they decide to ask their homeroom teacher for advice, he unexpectedly develops double nipples under the pretext of "improving the constitution of their nipples"! They look plain, but their nipples are erect... They need to get used to different stimuli... (lol) As best friends, they should lick each other's nipples... Wear toys during tests... The repeated nipple development makes them both urinate! Convulse! Double nipple orgasm!