Keisuke Isobe and Koume Satou lead a lackluster existence in a sleepy coastal town. However, their mundane lives take an unexpected turn when Koume's romantic interest shatters her heart. In the aftermath, she initiates a no-strings-attached arrangement with Keisuke, whom she had previously rejected. The two seek solace in each other to fill the void left by their emotional turmoil. Alas, complications arise when genuine affection starts to blossom, and the repercussions of their actions begin to impact everyone around them. Umibe no Onnanoko offers a stark portrayal of love, relationships, and the emotional toll paid by two youthful lovers.
