"Ayashinoyu Momoiro Bijin" is a manga series that blends elements of supernatural mystery, romance, and drama. The narrative centers around a young man named Kōichi, who moves to a rural town to live with his aunt after the death of his parents. The town is known for its hot springs, which are said to have mystical properties. Kōichi soon discovers that the inn where he is staying, Momoiro Bijin, is inhabited by a group of enigmatic women who are not entirely human. These women are yōkai, supernatural beings from Japanese folklore, each with their own unique abilities and backstories.

The protagonist becomes entangled in the lives of these yōkai women, particularly with the inn's proprietress, a beautiful and mysterious woman named Momoko. Momoko is revealed to be a kitsune, a fox spirit, who has lived for centuries and has a deep connection to the town's history. As Kōichi settles into his new life, he learns that the inn serves as a sanctuary for yōkai who seek refuge from the human world. The series explores the relationships between Kōichi and the yōkai women, as well as the challenges they face in coexisting with humans.

The plot delves into various supernatural occurrences and mysteries tied to the inn and its inhabitants. Kōichi often finds himself caught in the middle of these events, using his growing understanding of the yōkai world to navigate the complexities of their existence. Themes of love, loss, and the struggle for acceptance are woven throughout the story, as the characters grapple with their identities and the boundaries between the human and supernatural realms.

Key characters include Momoko, whose wisdom and grace guide much of the narrative; Yuri, a tsukumogami (a spirit inhabiting an object) who is fiercely protective of the inn; and Ayame, a water spirit with a tragic past. Each character's backstory is gradually revealed, adding depth to the overarching plot and highlighting the series' exploration of folklore and mythology.

The manga balances episodic storytelling with an overarching narrative, blending moments of lighthearted humor with darker, more poignant themes. The supernatural elements are intricately tied to the characters' personal journeys, creating a rich and immersive world that draws on traditional Japanese folklore while presenting a unique and engaging story.