"Nijiiro Koi Ryokan" is a manga series that centers around the lives of the residents and staff of the Hananoyu Ryokan, a traditional Japanese inn located in a rural hot spring town. The story primarily revolves around the inn's young heir, Shion Hananoyu, who returns home after her father's sudden death to take over the family business. Shion is determined to preserve the legacy of Hananoyu Ryokan, but she faces numerous challenges, including financial difficulties and the need to modernize the inn to attract new customers.

The narrative explores Shion's relationships with the people around her, including her childhood friend and employee, Tsubaki, who harbors unspoken feelings for her. Tsubaki is a skilled craftsman who helps maintain the inn and supports Shion in her efforts to revitalize the business. Another key character is Ritsu, a mysterious and talented chef who joins the inn's staff. Ritsu's arrival brings both culinary expertise and a complex past that gradually unfolds as the story progresses.

As Shion works to save the ryokan, she encounters various guests, each with their own stories and struggles. These interactions highlight themes of community, tradition, and personal growth. The series also delves into the dynamics of small-town life, where everyone knows each other, and the importance of preserving cultural heritage in the face of modernization.

The plot is driven by Shion's determination to overcome obstacles and her evolving relationships with Tsubaki, Ritsu, and the other characters. The series balances moments of lighthearted humor with emotional depth, creating a narrative that is both engaging and reflective of the challenges of maintaining a family business in a changing world. Through its exploration of love, friendship, and perseverance, "Nijiiro Koi Ryokan" offers a heartfelt portrayal of life in a traditional Japanese inn.