Kirina Hiura hails from Inakunijima Island, where he featured on the local soccer team before its dissolution. He subsequently joins Inakuni Raimon, relocating with the team to Inazuma Town to compete in the Football Frontier tournament under coach Zhao Jinyun. His initial development unfolds during matches such as the clash with Minodouzan, where he unveils his signature technique, Koori no Ya, to shatter defensive walls, showcasing strategic growth. He further refines his skills in combination moves, executing Meteor Drop alongside teammates Asuto Inamori and Sasuke Kozoumaru during pivotal matches, including the rematch against Seishou Gakuen.

Hiura exhibits a calm, analytical, and perceptive personality, consistently observing details others miss. His strong deductive abilities surface when he identifies Mutekigahara Fujimaru as the disguised Li Hao through behavioral inconsistencies and skill level analysis. A supportive nature emerges in his consistent concern for teammates, exemplified when explaining Nosaka Yuuma's health risks to Asuto Inamori and Haizaki Ryouhei to prevent further injury. He maintains a detective-like approach during investigations, such as tracking Ichihoshi Mitsuru's disappearance within a forest.

As a midfielder for Inazuma Japan in the FFI tournament, Hiura contributes offensively and defensively. His perceptiveness proves vital against international opponents; he recognizes prior training with Li Hao enabled players to evade rough tactics from South Korea's Red Bison. He participates in developing and executing advanced tactics like Ouja no Takt under Nosaka's leadership, and combination hissatsu techniques such as Death Crusher Zone with Kidou Yuuto, Fudou Akio, and Haizaki. His observational skills extend to match analysis, deducing Luci Fanos' hypnosis trick against the Shining Satans and later appreciating Sakanoue Noboru's adaptation of Koori no Ya.

Hiura's background includes a familial connection to his grandmother, referenced in his vow to uncover Li Hao's identity "in her name." His commitment to resolving mysteries underscores his role as an intellectual stabilizer within the team, frequently clarifying complex situations. Throughout tournaments, he balances tactical ingenuity with steadfast loyalty, reinforcing his reliability during high-stakes matches.