"Otohime Connection" is a slice-of-life anime series centered around the lives of four high school girls who form a band called Otohime Connection. The narrative unfolds in a small coastal town, where the girls navigate their daily lives, friendships, and the challenges of pursuing their musical aspirations. The protagonist, Aoi Hoshino, is a reserved and introspective girl who finds solace in playing the guitar. Her childhood friend, Yui Nakamura, is the energetic and outgoing drummer, often serving as the emotional anchor of the group. Rounding out the band are the bassist, Rina Takahashi, a pragmatic and level-headed individual, and the vocalist, Saki Fujimoto, whose enigmatic personality and mysterious past add depth to the group dynamic.

The story begins with Aoi and Yui deciding to form a band after discovering their shared love for music. They recruit Rina and Saki, each bringing their unique talents and personalities to the group. As they practice and perform together, the girls face various obstacles, including interpersonal conflicts, self-doubt, and the pressures of balancing schoolwork with their musical ambitions. The series delves into their individual backstories, exploring themes of identity, personal growth, and the importance of pursuing one's passions.

Throughout the series, the band's journey is marked by both triumphs and setbacks. They participate in local competitions, perform at school festivals, and gradually gain recognition within their community. The narrative also highlights the evolving relationships between the characters, emphasizing the bonds of friendship and mutual support that sustain them through difficult times. The coastal setting serves as a backdrop for many key moments, with the ocean symbolizing both the vast possibilities and the uncertainties that lie ahead.

As the story progresses, the girls confront their fears and insecurities, learning to trust in themselves and each other. The series culminates in a climactic performance at a regional music festival, where Otohime Connection must overcome their biggest challenge yet. The resolution of the story underscores the importance of perseverance, collaboration, and the transformative power of music. By the end, the characters emerge stronger and more united, having grown both as individuals and as a band.