TV-Series
Description
Gunkan, known as Captain Battleship in some adaptations, is a significant character introduced as the first of the Maruhage Empire's Four Heavenly Kings. He is defined by his complex past as a former friend and ultimate rival to the series' protagonist, Bo-bobo.

In terms of background, Gunkan was born as the oldest son of an average family in the Hair Kingdom. It was there that he met Bo-bobo and began rigorous training in the Fist of the Nose Hair under a master known as Master Juice. Consumed by a desire to be acknowledged and to find a purpose in life, Gunkan trained harder than Bo-bobo. However, despite his superior effort, the title of the Seventh Master of the Fist of the Nose Hair was given to Bo-bobo due to his heritage as a Hair Kingdom descendant. This rejection crushed Gunkan's pride and became the root of his animosity. He did nothing to stop the Maruhage Empire when it attacked the Hair Kingdom and was secretly glad to see it destroyed, deepening the rift between the two former friends. Following this, a period of wandering led him to befriend a creature named Flowerman, whose death at the hands of flower demons reignited his grudge and set him on his path of vengeance.

Gunkan's personality is a contradictory mix of sinister villainy and genuine sensitivity. As a high-ranking Hair Hunter, he is capable of great cruelty, having destroyed countless towns and exploited others' weaknesses without remorse. He is a skilled liar, often twisting the truth to paint himself as the victim and others, such as Heppokomaru, as the real villains. Despite these negative traits, he is not purely evil. He is shown to be a good leader to his soldiers, frequently partying with them, and possesses an emotional, sensitive side. This dichotomy is central to his role; his harsh exterior masks a deep-seated need for respect and acknowledgment from his rival, Bo-bobo.

Gunkan's primary motivation is his wounded pride and his desire to prove himself superior to Bo-bobo, whom he believes stole his rightful destiny. As a member of the Four Heavenly Kings, he serves Emperor Tsuru Tsurulina IV but secretly plots to use the empire's resources to further his own ambitions of ruling. His ultimate goal is not global domination, but to force Bo-bobo to acknowledge his strength, a fact revealed during their final confrontation.

In the story, Gunkan serves as an early major antagonist. He commands a vast military force from a sky fortress known as the Pomade Ring, which hovers above the destroyed Pupuu City. He is directly responsible for the destruction of Heppokomaru's hometown, creating a personal vendetta. He leads an army of elite warriors, including his second-in-command, a psychic named Suzu, and a group known as the Five Great Warriors. His role in the plot culminates in a direct showdown with Bo-bobo after capturing the character Beauty to lure his rivals into a trap.

Key relationships define Gunkan's actions. His relationship with Bo-bobo is the cornerstone of his character, evolving from fierce competitors and close friends to bitter enemies. His desire for Bo-bobo's respect is the hidden truth behind all his villainy. He also has a notable relationship with Heppokomaru, whose hometown he destroyed, and he commands a group of loyal subordinates, particularly Suzu, who remains by his side through his defeats.

Gunkan undergoes notable development throughout the series. His downfall comes when Bo-bobo uses a move he could never master, leading to a psychic vision where his true, vulnerable feelings are exposed. He admits he never meant what he said about the Hair Kingdom and that he always wanted Bo-bobo's respect. After his defeat, he is shown to be remorseful, running to apologize, though Bo-bobo comically strikes him down anyway. Following this, he is often found unconscious or in prison due to his failures, but he survives and later appears at a reunion, having seemingly moved past his grudge.

Gunkan possesses formidable abilities as a master of the Fist of the Nose Hair. After being rejected as the successor, he modified the art to fit his own style, calling it the Personalized Fist of the Nose Hair. This technique allows him to use his nasal hairs as powerful, versatile weapons. Some of his specific attacks include the Mermaid Lagoon, where he attacks with rolling nose hairs; the Bone Bone Going Fist, which drains the energy from an opponent's body until only bones remain; and his ultimate attack, Armageddon, in which he summons the Earth Defense Forces to fire lasers at his opponent. In addition to his nose hairs, he can weaponize his large ducktail hairstyle, extending it to great lengths to attack opponents or even support the weight of multiple people. As a user of Hajike, he is prone to bizarre, random behavior, such as accidentally destroying his own fortress or turning into an octopus, which is consistent with the series' absurdist humor.