Obscene: Mature Couples Swapping – The Agony of Wives in Their Thirties (2009)

Izumi, a housewife, is completely neglected by her husband Masao and has even been contemplating divorce. Just then, she reunites with Miki, a friend from her university club days. Hoping to recapture the fun they used to have, the two women—thanks to Izumi’s arrangement—end up living next door to one another.