The uke is a cross country athlete. He made the mistake of taking advise from an online website, in order to improve his time, resulting in lactating nipples. The seme is his best friend who helps the uke and releases the milk. Over time the ukes running improves and the seme confesses his love. They end up together and the lactating nipples end.
A Friend's Tiddies Are A Burden To An Otaku