Mai, who lives with her much older husband, starts working part-time, citing that she feels down when at home. In reality, it's a job as a partial model in a studio because of her beautifully plump lips. Unable to refuse the man who aggressively pursues her lips for higher pay, their interactions escalate from massage to kissing. Each visit leaves her trained to find pleasure through her lips. 'Hmm, something feels different...?' Her husband is oblivious. The lewd relationship she can never reveal.
