Hentai no kisetsu: Kôkotsu no ibuki

Original title: 変態の季節 恍惚のいぶき

Rumi is a popular novelist who writes about her own romantic experiences. One day, she happens to meet Noboru, a friend from her school days. Rumi is in a slump and approaches Noboru, who is troubled by his wife's infidelity, for the sake of her novel.