Sakuya Hosono, a 14-year-old student at Kamui Daimon Comprehensive Academy, serves as the mechanic of Jenock’s First Platoon, recognized for his green hair, black eyes, and signature glasses perched atop his head. A four-time Technology Contest champion, his technical mastery in LBX robotics shines through creations like the Dot Blastrizer, Trivhine, Val Diver, and the Blast Guarder shield—the latter co-developed with Takeru Kojou. A tactical linchpin, Sakuya engineers mission-critical strategies during operations ranging from freight train escorts to the capture of Eldar City and countering threats like Eldband. He leverages battlefield environments to outmaneuver opponents, deploying water towers to disable adversaries or exploiting drift ice to destabilize enemy formations. His analytical precision uncovers flaws in armor designs, driving collaborations to craft hybrid LBX systems that merge agility with laser-resistant defenses. Loyalty defines Sakuya’s bonds with the First Platoon. Initial frustration over Arata’s LBX damage evolves into steadfast camaraderie, as he bridges divides between Haruki and Arata, reinforcing unity. His quiet empathy surfaces in visits to an injured Arata and steady encouragement for Hikaru during emotional duress, underscoring his belief in collective reliance. Beyond tactics, Sakuya initiates covert projects like War Time’s secret weapon and meticulously allocates team funds to secure vital resources. Occasional social missteps, such as misreading Rinko’s cues, contrast his unwavering commitment to duty. A founding First Platoon member alongside Haruki, their shared history fosters seamless coordination. Sakuya stabilizes the unit, tempering Haruki’s impulsivity and anchoring the team to strategic discipline. His dual prowess in innovation and diplomacy cements his role as the platoon’s cornerstone.