Henri Hayao captains the Fukuhara High School Vanguard Club team alongside members Shion Kiba and Rin Hashima, sporting a red Vanguard circle. He has brown shaggy hair, wears round glasses, and typically appears in the Fukuhara High School male uniform—a black buttoned-up shirt. During the summer in the latter half of NEXT, he stops wearing his school jacket.

Initially timid, Henri possesses strong emotions and frequently demonstrates leadership qualities, often leaving a lasting impression. Participation in the Under20 Championship significantly boosts his confidence in cardfighting, leadership, and overall self-assurance.

His primary deck utilizes the Narukami clan, focusing on units with the Thunderstrike ability. His ace unit is Dragonic Vanquisher "SPARKING", and his G unit is Conquering Supreme Dragon, Dragonic Vanquisher "VBUSTER". The deck includes multiple critical triggers like Lightning of Triumphant Return, Reseph and Plasma Dance Dragon, alongside draw, heal, and stand triggers. For the U20 final stage, he modifies the deck for heavier Thunderstrike focus, replacing triggers such as Djinn of Rainy Duststorm and Deity of Love, Kama with Malevolent Djinn and Demonic Dragon Nymph, Cordo.

His Season 8 battle record includes losses to Shion Kiba, Rin Hashima, Kazuma Shouji, and Am Chouno, a win against Amaruda, and a loss to Dumjid. In Season 9, he secures wins against Relics in two separate encounters but loses to Toshiki Kai.

Rin Hashima has blocked him on his official Twitter account.