Read Man Up, Girl! Manga:
Sola and Kyung-ho are the perfect couple…almost. Three amazing years together and there’s only one teeny problem: he’s never given her an orgasm. When Kyung-ho discovers Sola’s trusty stash of sex toys (a girl’s gotta get off somehow!) a screaming row erupts and they break up. Cut to next morning and something’s off… Sola and Kyung-ho have switched bodies!