Gomu Kaimasen ka?

Tarou has finally set aside all frivolous expenditures and managed to save up a nice little nest egg for retirement. To celebrate, he invites Mio over for a special service. She'll sell him condoms and allow him to use them when to play with her. It's a lucrative job and Mio's found herself the perfect mark. How many condoms can she actually get him to buy?

(Source: Irodori Comics)