"Ride Your Wave" centers on Hinako Mukaimizu, a spirited college student who moves to a coastal town to pursue her passion for surfing. Her life takes a dramatic turn when she meets Minato Hinageshi, a dedicated firefighter who saves her from a fire at her apartment. The two quickly form a deep connection, bonding over their shared love for the ocean. Their relationship blossoms as they spend time together, with Minato encouraging Hinako to embrace her surfing dreams and face her fears.

Tragedy strikes when Minato dies in a surfing accident, leaving Hinako devastated and struggling to cope with her grief. In her despair, Hinako discovers that Minato’s spirit appears to her whenever she sings their favorite song, "Brand New Story," near water. This supernatural phenomenon becomes both a source of comfort and a barrier to moving forward, as Hinako becomes increasingly reliant on these fleeting encounters with Minato’s apparition.

As the story progresses, Hinako’s emotional journey is intertwined with her relationships with other characters, including Minato’s younger sister, Yoko, and his best friend, Wasabi Kawamura. Yoko, who initially harbors resentment toward Hinako, gradually comes to understand her grief, while Wasabi provides support and a grounded perspective. Through these interactions, Hinako begins to confront her loss and rediscover her independence, ultimately learning to navigate life without clinging to the past.

The narrative explores themes of love, loss, and resilience, with the ocean serving as a recurring metaphor for life’s unpredictability and the need to adapt. Hinako’s growth is depicted through her evolving relationship with surfing, which transforms from a shared passion with Minato into a personal source of strength and self-expression. The story concludes with Hinako finding closure, honoring Minato’s memory while embracing her own future.