Kaku

Biodata

Power Progression

Background and History

Kaku trained as a World Government assassin under Instructor Wo and became CP9’s youngest member. He went undercover as a shipwright at Water 7’s Dock One alongside Lucci; their original assignment concerned Pluton’s blueprints 90 143 235. After Kaku repaired Lin Mo’s damaged Flying Ship, Spandam reassigned him to infiltrate its crew. Kaku accepted the shipwright position while hiding his CP9 allegiance 100.

Life aboard the ship gave Kaku experience in maintenance, cooking and combat, particularly through his constant clashes with Enel. At Enies Lobby, he staged his capture, revealed his identity and returned to CP9. Spandam then ordered his execution. Lin Mo stopped Kaku’s subsequent suicide attempt and spared him, though he refused to heal him as punishment for the betrayal. Kaku renounced the Government and pledged loyalty to Lin Mo 104 119 148 149.

At Marineford, Kaku used a Reject Dial against Sengoku, taking a fatal impact himself. Lin Mo revived him after his body had been preserved for a month, at the cost of ten years of Lin Mo’s life. Kaku retained his memories and familiar habits, but the revival removed his emotions and desires. His behavior toward outsiders became markedly more ruthless, prompting Lin Mo to seek a way to restore him 490 504 505 508.

Later, after Kaku’s dangerous behavior and separation from Lin Mo, medicine supplied through Lu Qi’s arrangements helped him recover. He apologized to Lin Mo and returned to his former caring manner. Offered a bodily modification that might let him cultivate power in another world, Kaku chose to improve without risking his existing abilities 621 642.

Appearance

Kaku’s most recognizable feature is his long, square nose 90.

• Wears a cap during his early work at Water 7 90.
• Calls himself “this old man,” despite stating that he is eighteen when Red-Hair asks his age 143.

Personality

Before his revival, Kaku paired diligence and dry humor with a preference for avoiding unnecessary harm. He restrained Enel when the latter threatened bystanders, fought nonlethally when possible, and refused Instructor Wo’s demand that he kill the younger trainee Ye Qiu Luo 102 148 157 240. His loyalty was initially shaped by CP9’s training: even after Spandam turned on him, Kaku believed he owed the Government his life 148.

After joining Lin Mo by choice, Kaku took responsibility for the crew’s everyday needs and repeatedly pushed Enel to train. Following his revival, those habits and his loyalty remained, but his restraint toward outsiders did not; he killed three robbers and refused to help a drowning child. His former gentleness returned after his later recovery 119 505 642.

Abilities & Skills

Six Powers and Haki

• Uses all six of CP9’s Six Powers. Tempest Kick is the technique he has trained hardest; he also uses Geppo for aerial movement, Shave for speed, Iron Body for defense, and Kami-e to evade attacks 235 338 360.
• Uses Armament Haki in close combat and Observation Haki to locate or anticipate opponents. Enel’s repeated attacks helped sharpen his combat reactions 155 230 336.

Calm-Calm Fruit

• Creates silent spaces and conceals his presence, including from Observation Haki; he uses the ability for stealth and private conversations 152 215 248.
• Concealment does not make him invisible. In a small arena, Vista could still see and defend against him 215.
• As a Devil Fruit user, Kaku loses strength when sufficiently exposed to seawater or Seastone-laced water 161 182.

Swordsmanship and Shipbuilding

• Fights with two swords but learned swordsmanship largely on his own. Vista praised his talent while identifying his need for stronger practice partners and instruction 215.
• Repairs and modifies the Flying Ship, from replacing burned planks and securing gears to reinforcing its deck against lightning damage 100 171.
• Develops lightning-absorbing equipment and Seastone devices to counter electrical attacks and Devil Fruit users 119 199 336.

Equipment and Items

• Demon Spirit / Demon Blade Evil Spirit — a short sword given by Lin Mo that can split into two blades and wound souls 152 164 230.
• Lightning-Absorbing Device — a repeatedly improved tool used against Enel’s lightning and the Mink Guardians’ electricity; sufficiently strong attacks can destroy it 119 157 199 203.
• Seastone Net-Rope Gun — concealed equipment used to disable Devil Fruit users, including Enel and Ace 336 543.
• Tool bag — carries repair tools as well as concealed blades and combat devices 505 543.

Relationships

• Lin Mo — captain. Kaku’s undercover betrayal gave way to a pledge of loyalty; Lin Mo later paid the cost to revive him and sought to restore his lost emotions 100 149 504 505.
• Enel — crewmate and frequent rival. Their fights accelerated Kaku’s growth, while each has intervened to protect the other despite their arguments 119 133 148 157.
• Spandam — former CP9 commander who ordered Kaku onto Lin Mo’s ship, then demanded his execution 100 148.
• Instructor Wo / Woni — former Six Powers instructor. Kaku later opposed his lethal training philosophy and spared Ye Qiu Luo 235 238 240.
• Vista — swordsman who defeated Kaku in a friendly match and offered to teach him 215.
• Rayleigh — Kaku addresses him as “Master Rayleigh” 479.
• Little White — crewmate whom Kaku looks after and teaches everyday courtesy 209 338.

Notable Quotes

“I’m just an ordinary shipwright aboard Lin Mo’s ship.” 238

“Whoever stands in our way, I’ll kill them without a second thought.” 505