Appearance

In Anime and Original Manga

During her childhood, Mai had short hair with bangs that swept across the right side of her forehead, partially obscuring it. A decorative ribbon was perched atop her head. Her outfit typically consisted of a button-up shirt with long sleeves, layered beneath a cozy sweater, complemented by a pleated skirt and knee-high black socks.

Upon becoming an Onbusuman, Mai’s form shifted into that of an imposing, beast-like entity. Her head was oversized and round, with an unsettling, non-human face. Her torso resembled that of a turtle, and she had a thick, hairy tail that trailed behind her. However, after undergoing spiritual purification, she reemerged as a teenage version of her former self, once again dressed in the clothing she had worn in life.

In her current spectral form, Mai has taken on the appearance of a small, compact creature. Her head resembles that of a turtle, with a ribbon resting on top, while a separate, animal-like face appears beneath the turtle head. Her body is notably smaller, with short, stubby limbs, and she now wears a miniature dress that fits her petite frame.

In Age-Restricted Manga

Gallery

In Anime and Original Manga

In Age-Restricted Manga

This manga contains content intended for mature audiences. It explores complex themes and may not be suitable for younger readers. The storyline delves into deep character development, intense drama, and emotional narratives. Viewer discretion is advised.

Personality

During her lifetime, Mai was a warm-hearted, sociable, and spirited young girl. She harbored a strong ambition of becoming an idol and dedicated herself to this goal, often practicing alongside Rin and their friends. Mai held her dream in high regard and was quick to take offense when others questioned its value. Her friendship with Rin came to an abrupt end after Rin expressed doubt about the significance of being an idol, leading Mai to label her a traitor and sever their bond. However, upon discovering that Rin’s harsh words stemmed from the hardships of caring for her ailing grandmother, Mai’s heart softened, and she deeply regretted her reaction, longing for the chance to apologize.

After being freed from her Onbusuman form, Mai chose to remain by Rin’s side as a guardian spirit, determined to ensure that Rin pursued her singing talent and achieved success as an idol. In this spectral role, Mai’s personality became more blunt and headstrong, often coming across as harsh or rude. Her stubborn nature made her dismissive of Rin’s true aspiration to become a novelist, insisting that Rin’s life would be meaningless unless she followed the path of an idol. Mai’s blunt demeanor extended to her interactions with others, frequently resorting to insults without hesitation. Despite her inability to respect Rin’s current wishes, Mai’s loyalty and protective instincts remained intact, as she never hesitated to defend Rin against criticism or insults from others, reflecting her enduring affection and concern for her childhood friend.

Background

Born with a natural talent for dancing, Mai’s dream of becoming an idol took root early in her childhood. She gravitated toward girls who shared similar aspirations, hoping they could one day form an idol group together. After witnessing Rin Sawaki’s singing talent during a music class, Mai eagerly invited her to join their group, believing Rin’s voice was essential to their success. Together, along with other friends, they practiced diligently, with Mai’s enthusiastic personality helping Rin gain confidence and break out of her shell.

Upon discovering an opportunity to audition as Junior Idols, Mai encouraged her friends to seize the chance, convinced that performing on television could launch their careers. However, Rin was unable to participate due to her responsibility of caring for her sick grandmother. Neither Mai nor their friends fully grasped the gravity of Rin’s situation, with some suspecting dishonesty or attributing it to her mother’s negligence. Frustrated by what she perceived as an excuse, Rin lashed out, questioning why Mai valued becoming an idol so highly. Misinterpreting Rin’s words as a betrayal, Mai severed ties with her, believing she and her friends could succeed without Rin. When the day of the audition arrived, Mai found herself paralyzed by anxiety, realizing she couldn’t face the challenge without Rin by her side. Overcome with fear, she asked her mother to pick her up from the audition venue. Upon learning that Rin was now able to attend, Mai insisted on accompanying her mother to pick Rin up, intending to apologize for her harsh words. Tragically, their car was involved in a traffic accident on the way, resulting in both Mai and her mother losing their lives. Consumed by guilt and unresolved resentment toward Rin for what she perceived as a betrayal, Mai’s spirit lingered in the world of the living, bound by her conflicting emotions and destined to haunt her former friend.

Synopsis

Kintama Hunt Saga

Acrobatic Silky Arc

As Rin witnesses Okarun’s transformation and stumbles upon one of his lost kintama, she becomes increasingly aware of a strange weight pressing on her, slowly revealing the presence of the yokai Mai in her Onbusuman form.

Onbusuman Arc

After leaving the Kamigoe Police Box with Okarun in search of his missing kintama, Rin is suddenly crushed under the unseen force of the Onbusuman, shocking Okarun. He rushes her to the Ayase household, where Seiko identifies the yokai’s spiritual connection to Rin’s past. To purify Mai’s lingering spirit, Seiko suggests they visit both the site of her fatal accident and the idol audition venue. Expecting encounters with awakened spirits, she prepares the group—Rin, Okarun, and Momo—with protection and transport. As the operation begins, the Onbusuman reappears, reacting to Rin’s singing and growing in size.

When they arrive at the crash site, Mai’s spirit regains her lost memories, particularly her attempt to seek Rin’s forgiveness before her death. This release of regret allows Mai to break free from the yokai’s grip. She and Rin reconcile, their friendship restored through a heartfelt duet that weakens the Shining School Building spirit. As Mai’s spirit begins to fade, she confesses her jealousy of Rin’s natural charisma when singing—something Mai could never match, as her desire to be an idol stemmed only from trying to meet her mother’s expectations. Rin reassures her, affirming that her strength lies not in perfection but in her kind and cheerful spirit, earning her true admiration. Touched, Mai disappears in peace.

Danmanra Arc

The group gathers at the Ayase residence to celebrate their victory, but Mai suddenly reappears—now transformed into a strange floating spirit with a small body and an oversized turtle-like head. Seiko explains that she’s become a guardian spirit. However, Mai insists she cannot move on until Rin becomes an idol, believing it to be Rin’s true calling. Though Rin awkwardly confesses she now dreams of writing light novels instead, Mai dismisses the idea as impractical and mocks her lack of material—though Rin defiantly mentions a vampire-human romance story. The two bicker, while Momo teases Okarun about reading her letter during the Kur invasion.

The next day, Rin and Mai return to the house, welcomed by Bamora and Turbo Granny. When they discover Seiko is missing, Okarun questions Turbo Granny about the cursed diorama. A chaotic argument breaks out after Mai mocks her, leading to a scuffle. Eventually, Okarun pleads with Turbo Granny to help save Momo, even offering anything in return. Realizing the severity of the situation, she enlists Rin and Mai to rescue those trapped inside the diorama.

Following the destruction of the four seals and the release of the Fairy-Tale Card, Turbo Granny instructs Rin and Mai to lower the cursed trunk onto a black cloth and remove the figurines without touching them. Because direct contact would transport them into Danmanra, only Mai, as a spirit resistant to curses, can safely handle the objects. Yet out of spite, Mai refuses and instead forces Rin to act. She surrounds Rin in spiritual energy, forcing her into an embarrassing idol outfit and turning herself into a microphone. As the crowd cheers, Rin reluctantly begins to sing, realizing that if she refuses, she’ll be stuck like this forever.

Just as the situation grows desperate, Rin’s singing activates the gravity-controlling Onbusuman power, levitating the figurines out of the trunk. Backed by live music, Rin finds her confidence and gives a full performance, lifting all trapped players back to reality. However, the Fairy-Tale Card—possessing Unji Zuma’s body—escapes and targets Rin, attempting to break her spirit. Before it can succeed, Mai intervenes, declaring herself Rin’s producer and protecting her from mental manipulation. In retaliation, the Card erases Rin’s mouth, cutting off her ability to sing.

The battle escalates until the Count of Saint Germain arrives unexpectedly, turning the tide alongside Okarun, Bega, and Rokuro. Following their victory, Okarun begs Rin and Mai to sing again to rescue Momo and Turbo Granny from Danmanra. As they emerge, they discover Momo has been shrunk to palm size.

Days later, Seiko invites the students involved in the battle to dine at Goro Stamina Booster. Momo promises to call everyone again when more paranormal chaos strikes. But Mai barges in, claiming she and Rin are all the help needed. Aira, unfamiliar with Mai, mocks her, prompting Mai to retaliate by declaring that Rin is far more beautiful than her.

Current Saga

Kozuka Knives Arc

While observing Kouki Yukishiro in the school gym—brought there by her blackmailer—Rin is ambushed by the enemy, who summons the Severed Head Dribblers. She’s slammed into the basketball hoop before Mai can react. Aira arrives and fights the creatures, eventually finding Rin’s head floating in the air with Mai distraught beside her. Mai explains their enemies’ powers and asks how to save Rin. Aira states that, like before, they must find the power user.

Surprisingly, Rin regains consciousness even without her body. Mai is overjoyed, but warns them that Rin is now between life and death. If all of her life force spills from her severed neck, she will die permanently. When Aira is targeted, Mai intervenes but is pushed aside by Aira, who takes the hit instead.

Mai urges Aira to keep fighting and asks Rin if she can still sing. Rin responds that she can’t without a body. As one of the dribblers grabs Aira and heads toward the hoop, Mai’s small size renders her attempts to stop it ineffective. Aira manages to push Rin’s head through the hoop from the opposite side, restoring her body and allowing Mai to transform into a microphone. With her powers awakened again, Rin controls gravity to defend against the enemies.

While Rin is distracted by her embarrassing outfit, Mai spots Kouki’s head surrounded by pygmy spirits. Since Rin and Aira can’t see them, Mai approaches and forms an alliance with the pygmies. They create a human-like chain, weaving through defenders and forcing Kouki’s head through the hoop to restore her body. Returning to Rin, Mai starts singing again as Kouki explains that her blackmailer is Murakami. As they prepare to confront him, the gym begins to shrink and the Dribblers grow massive. Aira realizes Rin’s gravitational field is collapsing, and Mai warns that Rin, still inexperienced, can only sustain the power for a few more minutes.

With no time to spare, the group scrambles to locate Murakami—who is comfortably watching from his apartment as chaos unfolds.

Abilities and Powers

Gravitational Control

Urban Legend

The concept of the Onbusuman appears to be influenced by several traditional Japanese folklore creatures, each known for their habit of clinging to people’s backs:

• Konaki-jiji (The Wailing Old Man): Hailing from the Shikoku region, this yōkai takes on the form of either an elderly man or an infant. It deceives passersby into picking it up, only to increase its weight to an unbearable degree, crushing its unsuspecting victims under the strain.
• Obariyon/Onbu Obake (The Piggyback Spirit): Found in Niigata folklore, this mischievous entity leaps onto a person’s back, progressively growing heavier with each step. However, if the person manages to carry the spirit to its intended destination, they are rewarded with wealth and prosperity as a token of gratitude.

Etymology

• Kawabanga (川番): Mai’s surname is composed of the kanji for “river” (川) and “turn” or “guard” (番), symbolizing fluidity and vigilance.
• Mai (河舞): Her given name incorporates an alternative kanji for “river” (河) alongside the character for “dance” (舞), alluding to her natural grace and passion for performing.
• Onbusuman: This yōkai name is likely derived from onbu (おんぶ), meaning “to give a piggyback ride,” fused with the English suffix “-man.” The term may also phonetically reference subban (鼈), the Japanese word for “snapping turtle,” as the similar sounds of “Onbusuman” and “Onbusubban” suggest a linguistic connection.

Trivia

• Mai’s family name, her turtle-like appearance as an Onbusuman, and the design elements of her guardian spirit form may be playful nods to the catchphrase “Cowabunga,” popularized by the Teenage Mutant Ninja Turtles, aligning with her turtle motif and youthful spirit.