Eora, Igeo Jekkeo Anindeyo?

Seo-Hui, a superhero manga otaku, developed a drug to alter parts of his body with the single-minded goal of becoming a hero. He even forced himself to conduct human trials, but the drug's side effects caused his male genitalia to transform into female genitalia. Tae-O, who had long harbored a secret crush on Seo-Hui, seized this opportunity and approached him...

“It's not that you don't have one, senior. You just don't know how to use it, right? Want to test it out?”

(Source: MrBlue, translated)

Note: Includes two extra chapters.