In the anime BECK: Mongolian Chop Squad, the character known as Hyoudou is a supporting figure whose presence is primarily felt during the early part of the story centered on the protagonist, Yukio "Koyuki" Tanaka. He is often referred to by his full name, Masaru Hyoudou, and is known to Koyuki as a formidable presence during their middle school years. The perception of Hyoudou is one of complexity, as he is known to different people for contrasting reasons; to Koyuki and his friends, he is initially known as a bully and the leader of a group that torments students, but to those who understand music, he is known as a technically gifted guitarist.

Hyoudou is a teenager, appearing to be around the same age as Koyuki, placing him in his early to mid-teens during the main events of the series. He is characterized by his brown hair, which is cut short to ear length, and brown eyes. As the leader of what is known as the "Hyoudou gang," he wields significant influence and power within his school year, using intimidation to establish a position of dominance over his peers. In this capacity, he serves as an early antagonist for Koyuki, creating obstacles and conflicts that the protagonist must navigate as he begins his journey into the world of rock music.

However, Hyoudou's role in the story extends beyond that of a simple bully. He is a member of his school's light music club and possesses outstanding technical skill as a guitarist. This talent introduces a key nuance to his character and to the series' exploration of musical authenticity. When the gifted guitarist Ryusuke Minami hears Hyoudou play, he acknowledges the boy's remarkable technical proficiency but criticizes his style as being overly reliant on technique and devoid of genuine feeling or passion. This assessment draws a clear line between mere mechanical skill and the soulful expression that the series champions as the hallmark of truly great music. Hyoudou's family background also informs his character; his father was a guitarist for a band named Baumkuchen, but his parents are divorced, and he uses his mother's maiden name, a detail that hints at a more complicated personal life beneath his abrasive exterior.

Hyoudou's primary motivation regarding the protagonist evolves over time. He initially singles out Koyuki for harassment, treating him as a target for his bullying. This adversarial relationship persists until a critical turning point during the school's cultural festival. After Koyuki and Ryusuke perform, Hyoudou's perspective shifts. He approaches Koyuki not as an enemy, but as a rival, confessing that he now recognizes Koyuki's talent and abilities. This admission marks the beginning of a reconciliation between the two, and Hyoudou is later described by Koyuki and his friend Saku as someone who is not fundamentally a bad person. This development suggests that his earlier animosity may have been fueled by a competitive recognition of Koyuki's latent potential, which he could sense as a fellow musician.

Throughout his arc, Hyoudou's notable ability remains his high level of guitar playing. While he is never portrayed as having the same raw, emotional connection to music as Ryusuke or the developing talent of Koyuki, his technical precision sets him apart from casual players. His story concludes on a positive note, as he and Koyuki resolve their differences and he continues to pursue musical activities after advancing to high school. Ultimately, Hyoudou serves as an early foil who challenges the protagonist, embodying the distinction between technical skill and heartfelt expression, before ultimately moving from an antagonist to a respectful rival.