Kage is a central character in Ranking of Kings: The Treasure Chest of Courage, serving as the closest companion and steadfast supporter of the prince, Bojji. His name means shadow in Japanese, a direct reference to both his appearance and his abilities. As the last known survivor of the Shadow Clan, a group historically feared and exploited for their skills as assassins, Kage carries the weight of a tragic past. He was a young child when he witnessed the massacre of his entire family by the very kingdom they served, an event that forced him into a harsh life of survival on his own.

In the spin-off series, Kage’s personality is shown to be a blend of hard-won pragmatism and deep-seated kindness. Having grown up thieving and mistrustful of the world, he initially presents a cynical and street-smart exterior. However, the series consistently demonstrates that this is a protective layer. When not with Bojji, Kage actively seeks to help others, his natural empathy often putting him in situations where he goes out of his way to assist those in need, even when it inconveniences him or gets him taken advantage of. He is fiercely loyal and protective, having pledged himself as Bojji’s faithful friend after being moved by the prince’s unwavering kindness and tragic circumstances. This devotion is a core part of his identity, motivating him to support Bojji’s training and ambitions without fail.

His role in The Treasure Chest of Courage is to further flesh out his character through standalone adventures that occur during the timeline of the main story. The series explores his life both as an individual and as Bojji’s partner. One episode shows him being sent on an errand to find a rare ingredient, during which his helpful nature is both exploited and ultimately rewarded. Another story highlights his dynamic with Bojji as they are tasked with earning money, showcasing their clever, if naive, teamwork. The series also dedicates significant focus to his formative years, particularly in an episode that explores his relationship with his mother and a key encounter that shaped his worldview.

A pivotal event from his childhood, shown in the spin-off, involves a dangerous encounter that forces a young, frightened Kage to find his courage. During this time, he is saved by Sir Kyo, the top knight of the Kingdom of Bo. Despite the stigma surrounding Kage’s clan, Sir Kyo treats him with respect, commending his bravery and inspiring him to use his strength to protect others. This act of selfless heroism leaves a lasting impression on Kage, contributing to the heroic and caring individual he becomes. These glimpses into his past, including more screen time with his mother, illustrate the foundation of love and resilience that was instilled in him before his clan was destroyed.

Throughout the series, Kage demonstrates notable abilities inherited from his Shadow Clan lineage. These include enhanced stealth, agility, and the ability to blend into or manipulate shadows, which he frequently uses for reconnaissance, thievery, and combat support. The narrative of The Treasure Chest of Courage focuses less on introducing new powers and more on how he applies his existing skills and courageous heart to overcome everyday challenges and help those around him. His development is subtle but meaningful, showing a character who has moved from a position of fear and survival to one of active, courageous kindness, largely influenced by his bond with Bojji and memories of figures like Sir Kyo who saw past his clan’s reputation.