In Hyakkiya Tantei Jimusho: Hyakkiya Hikari no Youkai Jikenbo Episode 1, titled "The Mystery of the Devirginizing Mountain," viewers are introduced to Hikari Hyakkiya, a catgirl detective operating in the town of Azamati. Specializing in supernatural cases involving yokai, Hikari is tasked with investigating a series of mysterious attacks on women near a local mountain, rumored to be the work of a devious spirit. As Hikari delves into the case, she uncovers clues pointing to the involvement of a mischievous yokai known for its amorous exploits. Her investigation leads her through encounters with various town residents, each providing pieces to the puzzle. Utilizing her unique abilities and detective skills, Hikari confronts the yokai, aiming to put an end to its misdeeds. The episode blends elements of mystery and supernatural themes, characteristic of the series' narrative style. The animation effectively portrays the eerie atmosphere of the town and the enigmatic nature of the yokai, enhancing the storytelling experience. Overall, Episode 1 sets the stage for Hikari's adventures, establishing her role as a detective in a world where the supernatural and human realms intersect. The episode concludes with hints of future cases, inviting viewers to follow Hikari's journey in unraveling more yokai mysteries.