TV-Series
Description
Bowie Obochiyama, also known as Diamond Boy, hails from an immensely wealthy family wielding significant influence in southern Chiba. Nearly everything in the region belongs to his family's group, the "Golden Guardians," their oil-based fortune exceeding 100 trillion yen. As the son of a prominent businessman, he enjoys initial privilege and occasionally looks down on others.

He possesses spiky scarlet hair, light green eyes, and distinctive red eyebrows. His signature look features an unbuttoned yellow suit jacket over a white shirt adorned with three vertical purple, light blue, and light green triangles. A blue bowtie, yellow shorts, black tights, dark brown shoes, and light brown socks complete his ensemble. His expressions are highly animated.

Initially the youngest member of D4, an elite duelist group including Prince Kaiser, Fargo, and Issa, Bowie suffers frequent losses, leading others in D4 to underestimate him. This fuels internal conflict and envy toward ordinary lives despite his wealth. His early personality blends cheerfulness with pride, sometimes manifesting as childish behavior. He deeply respects Prince Kaiser, having known him since childhood and consistently lost to him in youth.

His path shifts upon encountering Win Kirifuda. Impressed by Win's dueling, Bowie invites him to Maihama Academy. Associating with Win and the fun-focused Duema Saikou Club Win forms leads to Bowie's expulsion from D4, with Karen taking his place. Demoted, he joins the Duema Saikou Club. Here, he sheds elitist attitudes, cares less about status, enjoys casual activities like snacking with friends, and embraces dueling for fun. His appearance changes slightly during this time, including temporary weight gain.

A major turning point arrives when his family's company faces bankruptcy after investing $2 trillion in a failed rocket resort project, partly due to a risotto mishap. This loss of wealth forces Bowie to rely on his own abilities. During the "Duel Wars" tournament, which limits card rarity for fairness, he competes without expensive cards and defeats Fargo, demonstrating resilience and growth. His primary motivation becomes restoring his family's standing through his own efforts.

He duels with a Light Civilization deck centered on Supercar Dragon and Mecha Del Dinero races, swarming the field with machine creatures using cards like Dran-Gorgini for protection. After leaving D4, his deck evolves to incorporate Dark Civilization cards and Mecha Angel Command units, with Tomikou King Gorgini En Gels becoming his new ace card.

An alternate-reality version exists in a reversed world, sporting bushy eyebrows, messy hair, and an incomplete school uniform. In this reality, his family is the school's poorest, contrasting his original status.

Notable traits include his knowledge of professional wrestling moves, used in physical confrontations. A recurring fan-driven joke labels him the "true heroine" due to his expressive reactions. Despite reduced circumstances, debt collectors avoid targeting him directly, partly fearing online backlash from pursuing a minor. His journey concludes finding genuine happiness with friends in the Duema Saikou Club, no longer defined by wealth or status.

In manga adaptations, he still duels Win Kirifuda early on and remains in D4, where official duels at the school coliseum dictate standing. He also demonstrates immunity to certain supernatural effects, surviving an attack from an evil god unscathed.