In the bustling streets of Akihabara, Yatsuki Nishizuru leads a seemingly ordinary life as a part-time worker, balancing his duties while caring for his younger sister Nanao. His world takes a surreal turn when a peculiar girl, Rokka Ayatsuji, drops into his life—literally. Despite her charming demeanor, Yatsuki and Nanao soon uncover Rokka's true identity as a Rokurokubi, a youkai with a hunger for souls and a bizarre ability to elongate her neck. As if this revelation isn't perplexing enough, Yatsuki discloses a haunting truth about Nanao—she exists as a ghostly spirit separated from her physical form. Amidst these startling encounters, a dark presence possesses a maid from the local cafe, prompting Yatsuki and Rokka to tackle the malevolent force with the help of Nagi, a seasoned medium and sister to the afflicted maid. In a desperate bid to reunite Nanao's spirit with her body, Yatsuki embarks on a perilous journey of youkai extermination, facing formidable adversaries to secure his sister's salvation. As the boundaries between the ordinary and supernatural blur, Yatsuki grapples with his newfound role in this hidden realm, where each confrontation poses a life-threatening challenge.