Monkey D. Garp, known as the “Hero of the Marines,” has a strong, fatherly connection with Koby. Over the years, Koby has grown under Garp’s guidance, not only in terms of strength but also in embodying the principles of a just Marine. Garp sees Koby as a beacon of what the Marines should stand for—uncompromising integrity, uncorrupted by the system’s darker aspects.

For Garp, Koby represents hope for the future of the Marines. Garp’s decision to step in and rescue Koby during the Hachinosu incident isn’t just about saving a promising soldier but about safeguarding his own ideals for a better, more honorable Marine Corps.

Koby’s Role in Garp’s Vision for the Marines

Koby embodies the version of a Marine that Garp has always strived to be—one who pursues justice while remaining unswayed by corruption. Over time, Koby has stood out as someone with a clear sense of right and wrong, untainted by the morally gray areas that other Marines fall into. Garp views Koby as the future of the Marines, someone who can uphold the values that Garp holds dear but may not have fully succeeded in maintaining throughout his own career.

This deep respect and belief in Koby’s potential play a huge part in Garp’s decision to rescue him from the Blackbeard Pirates.

Garp’s Guilt Over Ace’s Death: A Factor in Saving Koby

Garp’s motivation to save Koby is also likely influenced by his regret over Ace’s death. Despite being a Marine, Garp was emotionally torn during the Marineford War. He ultimately couldn’t save Ace, his adopted grandson, from execution. That failure left Garp with immense guilt and a desire for redemption.

When Koby is captured by Blackbeard, the situation echoes the tragic events surrounding Ace’s death. Garp sees this as a second chance to protect someone he deeply cares about. While he couldn’t save Ace due to his Marine obligations, rescuing Koby becomes a way for him to prevent history from repeating itself.

Garp’s Personal Beliefs Versus Marine Protocol

Despite being one of the most respected Marines, Garp has always had a rebellious streak, often choosing his personal values over strict Marine protocols. His decision to save Koby, even though it might conflict with the objectives of the higher-ups in the Marines, reflects his complex nature. Garp cares more about protecting individuals he believes in than strictly adhering to orders from above.

This decision further underlines Garp’s unique position within the Marines—he operates with a sense of justice that is often independent of the corrupt forces in the World Government. His actions are based on personal beliefs rather than blind loyalty to authority, which is why he is willing to risk his life for Koby.

The Contrast Between Saving Ace and Koby

One key difference between Ace and Koby is their respective paths in life. While Ace chose the life of a pirate, Koby followed in Garp’s footsteps as a Marine. Garp’s reluctance to save Ace during the Marineford War was partly due to Ace’s status as a pirate and his personal conflict as a Marine officer. In contrast, Koby is the ideal Marine in Garp’s eyes, making it easier for Garp to justify going all-out to save him.

This distinction highlights Garp’s complex role within the One Piece world—he’s caught between family and duty, but with Koby, the lines aren’t as blurred. Garp doesn’t have to choose between his Marine duties and personal bonds in Koby’s case.