Ayame Takaike, 34, works as a pool lifeguard utilizing her swimming experience from school days. She lives happily with her husband and beloved young son as a family of three. Recently, she's been receiving more and more advances from men at the poolside. Despite her responsibilities as a lifeguard growing heavier, she finds herself unexpectedly being approached and flirted with. Initially, she firmly rejected every advance, but by the third or fourth time, her resolve began to waver—leading her to experience her first-ever affair. In stark contrast to the routine, duty-driven sex she shares with her husband, the careful yet intense lovemaking quickly swept her away completely. Even now, she can't forget that shocking experience. Before her suppressed desires as a married woman explode once again, we'll be her partner!