Koby’s story began as an involuntary cabin boy for the Alvida Pirates, where he lived in fear and servitude until he was liberated by Monkey D. Luffy. Inspired by Luffy’s determination, Koby decided to pursue his dream of becoming a Marine, training alongside Helmeppo under Vice Admiral Garp’s supervision.

During the timeskip, Koby’s reputation grew due to his bravery during the Rocky Port Incident, earning him the title “Koby the Hero.” Despite his success, Koby faced challenges, including a failed mission to capture Boa Hancock, which led to his capture by the Blackbeard Pirates. With the help of Perona, his SWORD colleagues, and Garp, Koby managed to escape captivity, further solidifying his status as a heroic figure within the Marines.

Koby initially appeared as a small, timid boy with pink hair and round glasses. Over time, his rigorous Marine training transformed him into a lean and muscular young man, symbolizing his growth and determination. Koby’s updated Marine uniform reflects his rank, and his confident demeanor showcases his evolution from a frightened cabin boy to a capable Marine leader.

Koby is kind-hearted, determined, and deeply committed to justice. While initially timid and submissive, his experiences and training instilled in him a strong sense of resolve. Koby values life and often seeks peaceful resolutions, contrasting with the more aggressive methods of some Marines. His bravery and unwavering dedication to his ideals have earned him respect among his peers and recognition as a hero.

Romance Dawn Arc
Koby is introduced as a cabin boy for the Alvida Pirates, where he befriends Luffy and helps him defeat Alvida. This encounter sets Koby on his path to joining the Marines and pursuing his dream.

Post-Enies Lobby Arc
Koby reappears as a Marine trainee under Garp, demonstrating his growth in both strength and confidence. His reunion with Luffy highlights their mutual respect despite being on opposing sides of the law.

Rocky Port Incident and Beyond
During the timeskip, Koby gained fame for his heroic actions in the Rocky Port Incident, elevating his status within the Marines. However, his mission to arrest Boa Hancock ended in failure, leading to his capture by the Blackbeard Pirates. His dramatic escape with the help of allies, including Garp, underscores his resilience and resourcefulness.

Cross Guild Bounty
Due to his status as a hero, the Cross Guild has placed a five-star bounty worth Beli500,000,000 on Koby’s head, marking him as a significant figure even among pirates.

• Monkey D. Luffy
  Koby’s first ally and inspiration. Despite their differing roles, Koby admires Luffy and strives to uphold his own sense of justice.

• Helmeppo
  A fellow Marine and close companion, Helmeppo shares Koby’s journey of growth under Garp’s mentorship.

• Vice Admiral Garp
  As Koby’s mentor, Garp has played a pivotal role in shaping him into the Marine he is today.

• Boa Hancock
  Their encounter during Koby’s mission to arrest her highlighted his sense of duty, even in the face of overwhelming opposition.