Fuusuke Ninku, often referred to as Fuusuke of the Wind, is the main protagonist of the anime. He is a young boy of approximately twelve years old with an unusual and somewhat comical appearance; he is notably short and scrawny for his age but possesses a large head, oversized eyes, a long tongue that frequently hangs from his mouth, and black, slicked-back hair. His typical attire includes an orange collared shirt with white cuffs, red shorts, a blue backpack, and a pair of yellow and brown sneakers. He is often seen carrying a harmonica, which he plays to pass the time or lighten the mood among his companions.

In the aftermath of a great war, Fuusuke was the former captain of the prestigious First Division of the Ninku corps, a group of elite warriors whose power was feared by the very empire they helped to save. Following the empire's subsequent purge of the Ninku, Fuusuke’s fundamental motivation is a deeply personal and emotional one: to find his missing mother, a skilled feng shui master who was kidnapped by a man from the Imperial Army when Fuusuke was a child. This search forms the core of his journey, which he undertakes with his loyal and unconventional partner, a penguin named Hiroyuki.

Fuusuke’s personality is a blend of youthful innocence and mature composure. He is typically portrayed as calm, laid-back, and curious, often seen walking with his hands clasped behind his head. Despite the dangerous situations he faces, he rarely loses his cool, maintaining a level-headed demeanor that speaks to his experience as a former captain. Even so, he is very much a child at heart; he has a famously voracious and comical appetite, even claiming to eat as much as twenty men combined, and his hunger is a recurring source of motivation for his travels. While respectful and generally well-mannered, he can also be bluntly honest and somewhat naive about the wider world and social cues.

Fundamentally, Fuusuke possesses a powerful sense of justice and a pure heart. He is a pacifist at his core and strongly adheres to the principles of the Ninku style, which is notably non-lethal. Even when faced with enemies, he will often try to defuse a situation without violence. His compassion extends to all living things, and he is quick to risk his own safety to protect strangers in danger, demonstrating a selflessness that belies his age. This unwavering loyalty to his comrades and his desire to protect the innocent are constant drivers of his actions.

Early in his journey, Fuusuke is a solo traveler, but his role in the story expands as he reunites with other former Ninku captains. He becomes the de facto leader of a small band of surviving warriors, including the rooster Ninku Aicho and the snake Ninku Toji, as well as Toji's mechanically-inclined sister, Rihoko. His relationship with these comrades is key to the narrative. While he is undeniably the most powerful member of the group, the story reinforces that he is still a young boy who relies on the help and support of his friends to succeed, facing the empire's assassins not as a lone hero but as part of a team. He also has a significant adversarial relationship with former Ninku member Kisumi, who now serves the Imperial Army; their battles push Fuusuke closer to uncovering the dark secrets behind the empire he opposes.

Throughout the series, Fuusuke's development is subtle but important. He grows from a child on a simple, personal quest to someone who is actively trying to uncover a vast conspiracy that involves the fate of all Ninku. His journey forces him to confront the darker realities of the post-war world, including the propaganda that has turned the public against people like him. Despite these heavy revelations, he consistently retains his core identity, showing that his strength lies not just in his power, but in his unshakeable moral code, his immense resilience, and his unwavering spirit in the face of overwhelming odds.

Fuusuke is a master of wind-based ninjutsu techniques, a power that grants him incredible speed, agility, and devastating aerial attacks. He is able to generate immense gusts of air to disorient his opponents, propel himself through the air with acrobatic skill, and even create powerful tornadoes that can ravage entire battlefields. As the former captain of the 1st Ninku corps, he is recognized as one of the most powerful Ninku warriors, which is why he remains a primary target of the Imperial Army. His small, unimposing stature often works to his advantage, as enemies tend to underestimate him right before he unleashes the full force of his abilities.