[6] He was voiced by Shin-ichiro Miki in the first anime adaptation of the Eyeshield 21 manga, a 2003 Jump Festa OVA titled The Phantom Golden Bowl.

He soon learned the sport's rules and managed to successfully gamble on the winning teams, accumulating a large amount of money over the years.

He entered Mao Junior High, where he met another football fan Ryokan Kurita, who encouraged Hiruma to create his own team.

Hiruma and Kurita befriended their classmate Gen "Musashi" Takekura, who also decided to joined their club and the three friends made a pact to win the Christmas Bowl—the high school football league championship.

Since then, Hiruma refused to allow anyone else to take over Musashi's vacant kicker position except for himself, despite his lack of kicking ability, which hampered the Devil Bats' special teams.

Due to Deimon's remaining roster being filled with uninterested students that Hiruma blackmailed into joining, the Devil Bats had an abysmal first season and were eliminated early in both the spring and fall Tokyo tournaments.

This possibly explains the younger Hiruma's keen insight and strategic mind, his focus on offense over defense, and his refusal accept failure and willingness to win at all costs.

At the beginning of the series, Hiruma and Kurita, now in their second year of high school, attempt to recruit new members to the Deimon Devil Bats.

Hiruma's insight and strategic mind, especially his knack for devising trick plays and his psychological games, are critical in the Devil Bats' various matches.

[17][18] Despite leaving Deimon, Musashi has his family's construction company build new accommodations for the Devil Bats and maintains a cordial relationship with Hiruma.

The Devil Bats are able to complete the Death March, which heavily improves their strength and stamina, and Hiruma uses his winnings from playing blackjack in Las Vegas to fund Deimon's traveling expenses back to Japan.

In the Kantō tournament, Deimon defeats Shinryuji in their game opener—fulfilling Hiruma's desire for revenge against the school and Agon, who is humbled by Sena and Kurita in separate matchups against them— and go on to win their rematch against Ojo in the semifinals.

Sena ends up filling in as quarterback and is able to hold his own until Hiruma returns to help lead the team to victory, winning the Kantō tournament and allowing the Devil Bats to advance to the Christmas Bowl against the undefeated reigning champions Teikoku Alexanders.

To prepare for the Christmas Bowl, Hiruma arranges for best players from the Tokyo and Kantō tournaments to individually train each of the Devil Bats in one-on-one sessions and uses a hyperbaric oxygen chamber (which he attaches to a segway for transportation) to heal his broken arm.

During the hard-fought and grueling championship match, Hiruma stops using numbers and facts and instead relies on his own faith in his teammates, which his father takes note of.

After winning the Christmas Bowl, Hiruma is chosen to be one of Team Japan's two quarterbacks along with Kid for the International Youth American Football tournament due to his knack for trick plays.

[20] Even before this, Hiruma had previously spied on Team USA in New York City to acquire information on the top five American players known as the "Pentagram", who are the favorites for the coveted MVP title, which includes an NFL contract and $3 million.

Before the championship game between Japan and the USA, Hiruma follows Takeru Yamato to an underground casino attended by the Pentagram and is baited into playing Texas hold 'em against their quarterback, Clifford D. Lewis.

In the final game, Hiruma and Agon effectively work together by using a perfected version of Shinryuji's Dragonfly formation which helps lead a comeback for Japan against America.

In his third and final year of high school, Hiruma retires along with Kurita and Musashi and Sena is named as the Devil Bats' new captain.

[22] Some time later, Hiruma is chosen as one of two candidates from Japan for an open spot through the NFL's International Player Pathway Program, with the other being Sena.

[41] Erin Finnegan of ANN also noted the "demonic-looking" aspect of Hiruma, saying he is "like a predecessor of Ozu from The Tatami Galaxy with a love of football".