XL Joushi.

Office worker Saki Watase signs up for a side job reviewing products, only to receive a large box of XL condoms as her first assignment. She puts the package aside and tries to forget it until her strict and capable boss Keisuke Sudou escorts her home after a night of drinking and notices what she has.

When Saki explains the situation, Sudou offers to help her test the product himself, abruptly changing the tension between boss and subordinate into an attraction she never expected to confront. Behind his cold professional image, Saki begins seeing a different side of him, while returning to their ordinary distance at the office becomes increasingly difficult once the nature of their relationship has changed.