After a fight with her boyfriend, Yuu storms out of the apartment building and steps into the elevator—only to get trapped when it suddenly breaks down. With no way to call for help and her phone out of service, she's forced to spend time alone with a salaryman from the same building. As anxiety and impatience grow, they gradually grow closer, feeling each other's body heat in the confined space. Casual conversation turns deeper, and as they brush against each other in the tight quarters, emotions and desires surface that they'd never normally express. Tension and excitement rise, transforming their relationship into something entirely new.