Aoi, Mitsuri, and Miwa are adult fourth-year university students in the same surfing club. Mitsuri has secretly loved her childhood friend Aoi for years, but Aoi begins dating Miwa. When Aoi discovers that Miwa has been cheating and loses faith in women, Mitsuri insists she is different and proposes proving it by abstaining from sex for a month, asking him to grant any wish if she succeeds. Nagahama Mitsuri takes on a girlfriend-away NTR drama shaped by complicated romantic feelings rather than simple betrayal. After finally confessing the love she could never express, she begins a three-day trial of living with Aoi. Her bottled-up feelings explode, and she repeatedly begs to join body and heart with him, devoting herself completely. On the final day, an unexpected development changes everything.