Haruka, who works at a lingerie design company, is tasked with developing underwear that 'supports daring women,' but for her, who has no sexual experience, this is a challenge and she struggles. Meanwhile, a male employee gets an erection from Haruka's drunken big-ass panties and thrusts his huge dick into her... However, since that day, the project has been progressing smoothly, and thinking 'I need to do more perverted things to understand the appeal of underwear,' Haruka becomes addicted to sex, even her lewd body is co-developed...
