Aika is a saleswoman for a company that produces T-back underwear. Her sales performance always leads the company even though she specializes in selling to men. And her secret is... providing customers with the "experience" of the underwear right at home. Selling to men, of course, Aika also doubles as a model. Changing underwear right in front of customers, allowing them to admire, smell, and touch her round, full buttocks. Aika even lets customers have sex with her to "test" the seductiveness, elasticity, and durability of the underwear! No man can resist Aika's seductive power, the number of loyal customers is increasing, and sales are skyrocketing as a result...