Having spent most of her money, office worker Saki Watase takes on a side hustle. The pay is good, but the job is rather odd—she must make reviews of XL condoms. Once again, she reaches a dead end; no one she knows would need a condom of that size.

After a night out, Saki gets escorted home by her boss—Keisuke Sudou, a strict workaholic who often criticizes her work. To Saki's horror, the first thing Keisuke sees in her apartment is the large box of condoms. As it turns out, Keisuke is in need of an accessible variety of XL condoms and wishes to work toward improving such a selection.

Naturally, the only way to help Saki is to review the condoms together by having sex. Under the excuse that they are only sleeping together to test the condoms, Saki and Keisuke hide their unconventional office romance, dreading the day they inevitably run out of XL condoms and part ways.

[Written by MAL Rewrite]