Gakuto is a lean boy with deep-blue eyes and purple hair, which covers his eyes a bit. He also wears two white hairclips to the left side of his hair. He wears a plain light-blue uniform, with a pocket on his left side of the chest, and a symbol on the left part of his collar. He also wears black shoes.
At other times, Gakuto wears a blue kimono that has a black/light-blue pattern around his waist. He also wears a regal black/red cloak with yellow outlines.
Gakuto is a disciplined, serious individual, who has not been late to school a single day. He passes this virtue to his Dueling style, and believes the current Master Duels are fine as they are.
He becomes very irritated and agitated when people do not follow rules, especially Yuga Odo. Gakuto is significantly more reluctant to disobey Goha's ways than Luke or Yuga, he tends to panic whenever his friends to something that would break the rules and is quick to "beg" Goha for forgiveness when he thinks he's in trouble.
Gakuto finds himself conflicted between his desire to follow the rules and enforce them as the student council president, and the enjoyment he finds from hanging out with his new friends which often involves breaking the rules. He is largely unable to decline requests out of his fellow students, at times taking in too many tasks at once even largely mundane ones such as teaching math or filling a sport team vacancy, well outside the norm for student presidents (and unknowingly also breaking the rules at times due to being too focused in his current duties).
He is also honorable and stepped down from presidency after losing a duel, although he was easily reinstated afterwards showing he has very high charisma and significant approval. He does at times show a penchant for bad puns and is severely tone-deaf.
Gakuto's name means "Blue Moon" and "Student".
Gakuto has been the student council president for an unknown period of time, but is known to always arrive at 6:66:66 am, perform jogging and practice calligraphy as part of his daily routine.
Gakuto has been aware of Yuga's repeated attempts at breaking the Duel Disk's security causing him horror at Yuga's misconducts. At some point he witnessed Yuga and Tatsuhisa Kamijo enter a secret place and followed them. He soon discovers Yuga and Luke along the Hologram Man as he arrives with Romin Kirishima nearby. Gakuto is soon terrified that Yuga is trying to once more break into Goha's system security to install his new rules fearing everyone present will be penalized and by proxy taint his perfect record. Seeing Yuga's Duel Disk having energy problems, Gakuto offers to pedal his bike to provide power in the hopes of saving himself. When Yuga wins his duel he is surprised at everyone's Duel Disk changing into a 7-shape along with everyone's penalties being erased.
He is later seen witnessing Yuga and Luke's duel in Rush Duel format while explaining some game basics. He also finds himself shocked when learning that Yuga modified a Goha bot for his personal use.
Some time later, Luke requests Gakuto to dig information on Romin, fearing she could be a Goha agent spying on them, although he is unable to find anything significant. He goes along Yuga and the rest to his lab where he challenged Romin to a duel which she accepts, using a copy of Yuga's Spellcaster Deck. Gakuto desperately tries to prevent Luke from prying on Romin's guitar case. He witnesses the duel and praises Romin's ace card "Prima Guitarna of the Colorful Light".
In one day while performing his daily routine, he predicts his card fortune and draws "Fiendish Commander Yameruler". Soon Yuga drags him to a school room where they are trying some Rush Duel videos, and wanted Gakuto to sing, but he performs badly due to being tone-deaf. Eventually he finds himself overwhelmed by too much paperwork to stamp and realizes he spends too much time with Yuga and his friends, distracting him from his duties, and soon declares he will not entertain their requests any longer and bars them from doing Rush Duel while at school. Yuga proposes they duel about it and Luke adds that he steps down from the presidency if he loses, Gakuto accepts.
Before he can duel he is overwhelmed by multiple student requests which consume all his day. Although exhausted he decides to duel Yuga, honoring his agreement. As he and his assistants change clothes for his duel, donning a yukata, he has them draw and play his cards for him. Although he draws "Yameruler" early, he decides against using him, setting one monster and two Spell/Traps and ending his turn. It is Yuga's turn and he summons three monsters with which he reduces Gakuto's LP to 2,000. It is Gakuto's turn again and his assistants wonder if he is holding back out of wanting to preserve Rush Duels, which he denies. Yuga soon laughs to which his assistants take as mockery, but he states he is having fun dueling Gakuto and that he feels he wanted to have a good time too. Taking his words to heart Gakuto decides to handle his cards himself and summons "Yameruler". Subsequently and using dexterous Battle Position and ATK/DEF manipulation along "Yameruler's" effect, he is able to turn the tides and reduce Yuga to a mere 300 LP. Yuga counters "Yameruler" by using "Sevens Road Witch" and activating her effect that bypasses "Yameruler", Special Summoning "Sevens Road Magician" and winning the duel.
Gakuto admits defeat graceful and as promised steps down from the Student Council despite Yuga telling him it was not needed as it was Luke being selfish. Soon an emergency election is held which Gakuto wins by a landslide, easily defeating Luke and is thus reinstated in the presidency. Yuga subsequently modifies Kaizo to stamp papers for him, giving Gakuto more time to keep Yuga's friends in check.
Gakuto plays a Stall Deck based around "Fiendish Commander Yameruler", which prevents both players from Tribute Summoning high Level monsters, making it more difficult for the opponent to summon their ace cards. He compliments this strategy with monsters that have typically higher DEF. When attacking, Gakuto relies on "Shield & Sword" to use his monsters' high DEF for aggressive purposes, then he either switches his monsters back to Defense position after they attacked or removes them from the field so the opponent can't capitalize on their low ATK.