Saburō Yamada, third son of the Yamada family, occupies the role of youngest member in Ikebukuro’s Buster Bros!!! under the stage name MC.L.B (Little Brother). Possessing a genius intellect and multifaceted talent, he thrives across diverse fields. Though once tempted by delinquency, he rejected this path after his brother Jiro embraced it, choosing instead to model himself after the eldest sibling, Ichiro, whose disciplined example he strives to emulate.

Politely restrained in public, Saburō reveals a cutting edge in private, often mocking those he deems beneath him—a trait born of arrogance and a defensive wariness toward forming bonds. His analytical mind gravitates toward strategic hobbies like chess and card games, while his isolation stems not from indifference but a quiet yearning for lasting connections.

A self-aware "brother complex" fuels both loyalty and rivalry toward Ichiro and Jiro, anchoring his familial identity. Beyond rap battles, his skills extend to hacking, and his signature chokers underscore a calculated aesthetic. The solo track "New Star" mirrors his ambition, while his personal mantra—"Everything that rises sets, and everything that grows, grows old"—betrays a reflective streak beneath his aloof exterior.

In group conflicts and territorial rap clashes, Saburō’s tactical ingenuity proves pivotal, balancing cerebral precision with flashes of vulnerability. His narrative orbits the tension between intellectual self-reliance and an unspoken hunger for belonging, weaving pride and loneliness into a quest to define himself beyond the shadows of his brothers.