Yui Misaki, a big-titted married woman suffering from a sexless marriage, meets beauty consultant Katayama through a friend's introduction. Using his special oil and expert techniques, Katayama introduces her to pleasures she's never experienced before, awakening her curiosity toward anal stimulation. Drawn into its allure, Yui becomes deeply satisfied with his treatments and grows increasingly dependent. Following her desires, she willingly accepts even the most embarrassing acts. Her transformation perfectly embodies a woman who has awakened to anal pleasure.