Fumie, “Sex-chan” is a single office worker in her twenties whose only purpose in life is to have sex. She spends her days looking forward to having sex with someone. In the morning, noon, and night, whether it’s a regular person or someone new, male or female, it doesn’t matter. Just like breathing in or drinking water, she enjoys it every day.

In high school, she suffered from aphasia, learned sex is a way to communicate with others without words, and improved her aphasia. After that, her “honest relationship” can only be achieved through sex, continues to have physical relations with people she feels comfortable with and with whom she would like to know more. However, people around her begin to get married and have a baby; even her long-time friend with benefits gets married too. Should she give up sex to have “normal happiness” like others, or…?

She registers on a matching app and meets Takahashi, who hates sex. In addition to Fumie, there are also “Highly Educated-chan” and “Love Affairs-chan” who seem to be “normal” but have sex-related problems and long for “normal happiness” in the following episodes!