Ryō Hokari takes his name from the sports drink Pocari Sweat and stands as the primary rival to protagonist Cota Coga. His Bottleman partner, Aquasports, employs water-based attacks, including the signature Poseidon Trident technique that launches three bottle caps simultaneously to resemble a trident.

Initially clashing with Cota over their opposing battling styles and philosophies, Ryō's rivalry transforms into a reluctant partnership during a joint training arc. This alliance culminates in them teaming up to confront the final antagonists, Yujiki and George Muto, by the end of the first season.

Ryō's background stems from intensive training under his father, Io Hokari, president of the Bottleman Association (BMA), an upbringing that initially strained their bond. During the BMA crisis involving a rogue AI, Ryō reconciles with Io after returning a red Aquasports DX Bottleman to him in the hospital. Io subsequently resigns as BMA president, his doctor hinting at undisclosed health concerns influencing this choice.

Following the crisis, Ryō aids Cota in evading reporters and engages him in a final, heartfelt Bottleman battle within a park. During this match, Ryō reflects on how Cota reignited his passion for the sport and facilitated his reconciliation with Io, expressing regret over not meeting Cota sooner.

The next day, Ryō publicly announces his retirement from competitive Bottle Battling to succeed his father as the new president of the BMA, a decision portrayed as emotionally weighty yet resolved.