Running short of money, office lady Saki Watase is introduced to a part-time job where she's tasked with reviewing XL-size condoms. While receiving an escort home after a night of drinking, Saki's "demon" boss Keisuke Sudou notices that she's carrying a large quantity of condom. Once Saki explains her circumstances, Keisuke reveals that he is XL-size. A romance between the two thus begins.
Florencia Fazzarino Valente is an Argentinean girl, with Italian roots, who lives in Buenos Aires and works in a grocery store, helping out in her friends' band every once in a while. When the singer gives up, she finds herself taking her place and having to accept to sing at a party held at the Fritzenwaldens', a German-Argentinean family. But little does Flor know that her life is going to be connected to the Fritzenwalden family for ever.