Ain

Biodata

Power Progression

Appearance

• Hair: Medium-length blue hair, later described as shoulder-length 1 272.
• Build: Slender, with firm, visibly defined arm muscles when she tenses them 7 95.
• Usual clothing: A sleeveless top and very short shorts during early Guerrilla Unit training 28.
• Uniform distinction: Entitled to wear a Justice Coat upon becoming an ensign 25.
• Formal clothing: Wears a black satin spaghetti-strap dress and carefully applied makeup when attempting to approach Naito at night. This elaborate preparation is unusual for her daily routine as a Marine 272.

Personality

Ain is generally levelheaded, resilient, and demanding of herself. During recruit training, she continued working through hardships that left Binz complaining. He could not remember seeing her cry before her fear for Naito finally overwhelmed her after the Golden Lion confrontation 190.

She treats Naito as a benchmark rather than accepting the gap between them. After graduation, she challenges him to a spar specifically to measure how far ahead he has become. Later, frustration at being unable to help him against stronger enemies renews her determination to improve 6 111.

Her sense of Marine duty is strong. She questions the decision not to attack the Charlotte Family and Beasts Pirates merely because they are not the unit’s immediate targets. However, she also rejects belittling colleagues assigned to less spectacular work, arguing that their everyday duties contribute to peace 52 117.

Her romantic assertiveness develops alongside her affection for Naito. Initially embarrassed by teasing about him, she eventually confesses openly, initiates kisses, and refuses to abandon her pursuit when he rejects the label of dating. She becomes openly jealous of rivals, but still avoids putting him in a difficult position during official business 78 191 266.

Abilities & Skills

Return-Return Fruit

Ain produces peach- or pink-red flame-like energy that reverses a target to an earlier state. Its demonstrated effects extend to people, manufactured objects, and substances created by other abilities 6 123 171.

• Age reversal: Regresses Trebol from an adult into a teenager during combat; he and Baby 5 are subsequently brought back as children 171 173.
• Potential erasure: Ain judges that another application would reverse Trebol beyond his birth and make him disappear, so she stops 171.
• Weapon removal: Erases Don Krieg’s Mighty Battle Spear by returning it to a time before its creation 123.
• Removal of generated substances: Makes Trebol’s large mass of mucus vanish, freeing Binz’s vines to restrain him 171.
• Ranged attacks: Throws separate balls of Return energy at opponents 6 22.
• Close-range attacks: Coats her palm and short swords with the same energy 7.

Her early power has explicit limits: she cannot yet reverse twelve years in a single application during her post-graduation spar. Against Luna, Return briefly erases the flames it strikes, but Luna immediately generates more 6 22.

Six Powers

Ain progresses from individual techniques to proficiency in all six of the Marines’ physical disciplines 6 94.

• Soru: Closes the distance to Naito during their spar 6 7.
• Geppo: Crosses the sea with Binz to board the fleet’s lead ship 111.
• Tempest Kick: Launches crescent-shaped vacuum slashes, splitting Don Krieg’s armor and clearing pirates from the deck with successive attacks 123.

Armament Haki

Ain first awakens basic Armament Haki Coating, receives direct instruction from Naito, and later trains in Hardening under Gion 94 95 112.

• Masters Hardening during the royal escort voyage 145.
• Has not mastered Observation Haki at that point 145.

Dual-Blade Swordsmanship

Ain fights with two short swords and can combine their slashes with Return energy. Naito considers her swordsmanship decent during their early spar, but evades every attack because of the difference in speed and overall strength 7.

Investigation and Staff Work

As Naito’s secretary, Ain handles communications and assists with operational information 94 128.

• Proposes infiltrating a Sabaody shipyard under Naito’s concealment rather than continuing ineffective surveillance outside 18.
• Uses a dedicated communications Den Den Mushi to contact Ship Six and arrange the collection of captured pirates 94.
• Records images of Naito’s battles for newspaper coverage 94.
• Relays Sengoku’s orders concerning the Germa conflict and Judge’s attendance at the Reverie 128.
• Explains the restriction preventing Marine and government ships from approaching within three kilometers of Amazon Lily 255.

Equipment / Weapons / Items

• Two short swords — Carried at her waist and used with Return-coated attacks 7 170.
• Justice Coat — Personally placed on her shoulders by Zephyr at her commissioning ceremony 25.
• Communications Den Den Mushi — Used for contact with Naito’s ship and incoming orders 94.

History

Recruitment and the Marine Guerrilla Unit

Ain trains under Zephyr alongside Naito and Binz. During Weevil’s attack on their final assessment voyage, she offers to fight despite Zephyr’s order to withdraw. After the crisis, she warns Naito that his illusion might not have deceived Weevil’s Observation Haki had the attacker remained calm 1 2.

Following their return, Ain challenges Naito to test the distance between them. Her Return attacks and swordsmanship fail to touch him, and she concedes defeat. Watching him immediately resume his demanding training reinforces her respect for the work behind his strength 6 7.

At Sabaody, she helps investigate the shipyard and later provides ranged support against Luna. Luna blocks her Return projectiles and retaliates with a flaming slash, forcing Naito to intercept it 18 21 22.

Ain is formally commissioned as an ensign and selected for Zephyr’s newly formed Marine Guerrilla Unit. Initially assigned miscellaneous duties alongside Binz, she continues intensive training before becoming Naito’s secretary aboard his ship 25 26 29 94.

Independent Combat and Dressrosa

Ain’s growing strength allows her to handle ordinary pirates decisively. During the attack on Don Krieg’s fleet, she erases his signature weapon and defeats him with Tempest Kick, then helps clear the remaining pirates from the deck 123.

In Dressrosa, she leads Marines into the underground facility and fights alongside Binz and Sanji. Her Return ability removes Trebol’s mucus and regresses his age, helping the group capture him. They return with other Donquixote Family members in custody, and Naito singles out her contribution for praise 170 171 173.

Confession to Naito

After Naito survives his confrontation with the Golden Lion, Ain embraces him and cries, admitting that she feared losing him. She then confesses through her first kiss and initiates another, which he returns 190 191.

Naito refuses to describe them as dating. Rather than withdrawing, Ain takes his response as confirmation that he does not dislike her and resolves to keep pursuing him. When he subsequently rejects a date because he wants to train, she simply proposes training together 191 193.

Rivalry with Hancock

By the Amazon Lily mission, Ain openly presents herself as the woman who pursued Naito and intends to remain at his side. When Hancock boards the ship and displays affection toward him, Ain kisses him in front of her and declares that she will become his wife 254 255 262.

Ain’s insistence that Naito would never love a pirate precipitates Hancock’s lovesick collapse. Alarmed, Ain calls for Naito and worries that the incident could disrupt Headquarters’ plans. Hancock recovers immediately upon seeing him 263.

Their rivalry later prevents either woman from approaching Naito privately: Hancock drags Ain into her own room, and they spend the night watching each other while Gion reaches him instead. Ain recognizes afterward that Gion exploited their mutual distraction, but remains determined to stay beside Naito 272 273 274.

Later Operations

During the renewed Golden Lion operation, Ain recognizes that the officers cannot intervene in the main battle and directs them toward the other pirates on the floating island 279.

She is deeply concerned when Naito leaves to investigate Charlotte Linlin and Loki, knowing that his freedom of movement does not guarantee he will limit himself to reconnaissance. After his return, she witnesses his Conqueror’s Haki Coating and reacts with pride when Aokiji declares him strong enough to serve as a Marine Admiral 287 291 294.

Relationships

• Naito — Classmate, superior, instructor, and romantic interest. His dedication makes him her original training goal; she later pursues him openly despite his refusal to call their relationship dating 6 7 94 95 191.
• Zephyr — Teacher and founding commander of her unit. He guides her physical training, encourages her to turn frustration into motivation, and acknowledges her ability to carry out responsibilities independently 26 28 111.
• Binz — Fellow recruit and frequent combat partner. They bicker, but cooperate effectively against Don Krieg’s fleet and the Donquixote Family 78 123 171.
• Gion — Admired senior, Haki instructor, and eventual romantic rival. Ain initially hopes to become a Marine like her and Tsuru 111 112 274.
• Doll — Supportive senior who praises her progress and frequently teases her about Naito and potential rivals 111 254 255.
• Sanji — Junior companion whose talent and determination she recognizes. He supports her pursuit of Naito and congratulates her after her confession 142 191.
• Boa Hancock — Rival for Naito’s attention. Ain repeatedly invokes the distinction between Marine and pirate to challenge Hancock’s hopes 262 263 274.
• Tsuru — Professional idol whom Ain explicitly names as a model for the Marine she wants to become 111.

Notable Quotes

“I should at least find out where my goal stands, shouldn’t I?” 6

“But now I understand that Naito doesn’t dislike me either. That’s enough.” 191

“Because if I still cared about shame, I wouldn’t be able to stay by Naito’s side.” 255