Sarah is so tired of getting ignored because she is flat chested. When her crush at school starts dating a girl with big boobs, Sarah decides to take matters into her own hands and search for a way to make her boobs bigger. She finds an article online about how you can blow-up your boobs to make them bigger by doing a series of breathing exercises. She decides to give it a try and concentrates on them growing while sucking in air. Pretty soon they start getting big enough to stretch out her shirt, but that's not enough for Sarah. They need to be bigger than the girl at school! She keeps blowing them up until they are so big they burst out of her shirt, popping the buttons. She admires her new huge breasts for a bit, noticing how small her bra is on them now, before heading out to show them off to the boys in class.