|Favorite food||Napolitan spaghetti|
|Anime debut||Yu-Gi-Oh! SEVENS episode 8: "Post-Apocalypse and Napolitan"|
Yoshio is a short and skinny young boy with pale skin and pink eyes like his mother, though his hair is back and cut back at the sides and back while it is longer at the top and concealed under his cap when he wears it. He dresses in a sailor-style school uniform; a white shirt and shorts with a black lining held up with a black belt, white socks, black shoes, and a white sailor's cap with the symbol of the Goha Corporation on it.
When he tries to become like Good Max, Yoshio wears a cosplay suit of his favorite hero that also modulates his voice. The suit makes him appear as a tall, darker-skinned muscular man, wearing a black jacket with maroon shoulders tipped with golden spikes over a blue undershirt and black superhero-style shorts, maroon arm-guards with golden spikes on the backs of the hands and knee-high boots with golden knee spikes, a maroon belt with a golden buckle and holes, and a charcoal-colored helmet with silver horns, a yellow pattern on the top resembling an explosion, and a face mask with half-moon shaped red eyes and a mouth section designed to look like a jagged maw in two different shades of grey. The helmet is split in two after his Duel with Luke, though he later repairs it.
Yoshio is timid and excitable by nature, and prone to making hasty and ill-informed decisions on the fly; he misinterpreted Luke's advice to look after his mother due to Luke's coincidental use of his favorite hero's catchphrase and decided Luke should convince his mother to let him Rush Duel after his mother threatened not to make his favorite meal. He is shown to be passionate about Rush Dueling, enjoying his Rush Duel with Luke despite losing. After he takes Luke's advice, Yoshio realizes that he was trying to mimic others and that he should tell his mother his true feelings. He cares deeply for his mother and his favorite food. According to his mother, Yoshio is similar to Yuga.
Yoshio speaks very politely normally, but when he tries to change himself as "Yoshio the King of Combat", he puts on a gruff and tough-talking front, calling his mother his "mama" as Good Max does and often using the terms "destructive" and "hellish" as descriptors.
「安」 can mean "stability", "peacefulness", or "inexpensive"; 「立」 means "standing up". Together, the two characters can also be written as "Adachi", which is one character off from 「アダチル」 (adachiru), abbreviation for "adult child(ren)".
Yoshio learned about Rush Duels, and he decided that he wanted to try them, though his mother forbade him from doing so and threatened not to make napolitan spaghetti for him again. Conflicted over what to do, Yoshio wrote to Luke in the Goha 7th Elementary Newspaper, and Luke suggested that he take care of his mother and wished him good luck in English. Yoshio misinterpreted Luke's advice as suggesting he do so in the same manner as Good Max, so he began wearing a Good Max cosplay suit and talking like Good Max, though this only made his mother fear that Rush Dueling had turned him into a delinquent.
Yoshio bore a grudge against Luke and decided to have him convince his mother to let him Rush Duel. A week after first writing to Luke, Yoshi, Masahiko and Toshihiko cornered Luke, Yuga Ohdo and Gakuto Sogetsu before a vending machine and refused to let them use it unless Luke Dueled him. Luke himself showed disdain for Yoshio calling himself the "King of Combat", as he viewed it as similar to the title of "King of Duels", a title he believed only he should hold. Yoshio quickly played his "Beast Gear World" Field Spell Card and empowered his Beast Warrior monsters while weakening Luke's Dragon monsters. Despite the handicap, Luke was able to reduce Yoshio's LP with his "Rush Dragon Dragears". He told the group about his situation and vowed to have Luke convince his mother to let him Rush Duel, though Luke claimed he wouldn't be able to do so, as he was going to win the Duel. Yoshio Tribute Summoned "Catapult Devilkong, King of the Beast Gear World" and destroyed Luke's defending monsters with its effect, then destroyed "Dragears" itself and reduced Luke to 500 LP. Luke was able to comeback by destroying "Beast Gear World" with "Dragonic Slayer" and re-Summoned "Dragears", vowing that he wouldn't change, but would change the world around him as he defeated Yoshio and broke his helmet. After the Duel, Yoshio and his friends shared drinks with Yuga and his friends, Yoshio gushing about the Rush Duel despite his loss. Luke told him not to use the title of "King of Duels" again, and Gkuto pointed out they still had the problem of convincing Yoshio's mother to let him Rush Duel. Yuga offered to help Yoshio with one of his Roads, though Luke asked Yoshio if he was sure that was what he wanted. As he walked home that evening, Yoshio thought about what Luke had said and decided to tell his mother how he really felt. When he got home, Yoshio told Mimi that he really wanted to Rush Duel, and his mother told him he would have to keep up his studies as well, serving him napolitan spaghetti for dinner and leaving Yoshio overjoyed.
Luke later called Yoshio to ask him to bring the Goha 7th Newspaper Club to the Seven Hells Hall. Yoshio (in his Good Max costume) took his tricycle to get the Newspaper Club and brought them to the Hall just as Kaizo was about to disqualify Yuga for using "Sevens Road Magician", whose legality was under question. The Newspaper Club were able to prove the card's legality, allowing Yuga to continue his Rush Duel with Roa Kirishima. Yuga brought out "Sevens Road Magician", but Roa destroyed it and reduced him to 500 LP, causing Yoshio to worry that Yuga wouldn't be able to win without "Sevens Road Magician". However, Yuga was able to retrieve "Sevens Road Magician" from his Graveyard and defeat Roa.
Yoshio uses a Post-Apocalyptic Deck, composed of the Beast-Warrior-Type "Beast Gear World" series. His strategy largely revolves around empowering his monsters with the Field Spell Card "Beast Gear World" while also weakening his opponent's monsters.
|Tatsuhisa "Luke" Kamijo||8||Lose|