Seiko Ayase — Dandadan

Biography

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Dandadan

Seiko Ayase綾瀬星子

Momo Ayase's grandmother and a spirit medium

Seiko Ayase is Momo Ayase's grandmother and a formidable spirit medium in Yukinobu Tatsu's manga Dandadan. Working under the name Santa Dodoria, she protects her home with spiritual barriers and becomes a blunt-spoken adviser to Momo and her friends when their encounters with curses, yokai, and aliens turn dangerous. Her strikingly youthful appearance contrasts with her role as the household's experienced, no-nonsense guardian.

Biography

A grandmother with an unusual profession

Seiko lives with and looks after her granddaughter Momo, whose family has a background in spirit mediumship. Seiko practices that tradition openly: she is known professionally as Santa Dodoria, maintains spiritual protections around the household, and treats the occult as practical work rather than distant folklore.

Her direct manner can be abrasive, particularly when Momo challenges her, but the friction exists alongside genuine care. Seiko's early guidance gives Momo an adult who understands the supernatural danger surrounding her without pretending that every problem can be solved by reassuring words.

Okarun and the first curse

After the spirit called Turbo Granny curses Okarun, Seiko intervenes and helps Momo understand what they are dealing with. She uses her spiritual knowledge and household wards to restrain the immediate threat, then gives the younger pair practical advice as they work toward breaking the curse.

Seiko's relationship with Okarun develops through those early emergencies. When he tries to compensate her for the help he has received, she urges him to repay kindness by helping someone else when they need it, expressing a principle of mutual support rather than keeping score.

A refuge between disasters

Seiko's home becomes a recurring place where Momo and her companions can eat, recover, argue, and compare notes. Seiko cooks for the group and supplies a mixture of hospitality and sharp criticism; even the supernatural company around the household gradually becomes part of its hectic routine.

Her assistance is not limitless. As a medium whose techniques involve spiritual powers associated with particular places, she must take territory and preparation seriously. That restriction helps explain why the younger characters cannot simply wait for Seiko to resolve every encounter herself.

Personality and Motivations

Seiko is outspoken, self-assured, and quick to scold. She does not cushion every warning, but she also does not confuse toughness with indifference: she protects Momo, helps frightened or injured youngsters, and feeds people who need a place to recover.

Her humor is irreverent, and her intimidating confidence has a comic weak spot: she enjoys compliments about her youthful looks, as Jiji discovers. Her advice can be remarkably generous, too. When Okarun tries to repay her, she tells him to help someone else in need rather than settle a debt to her.

Appearance

Seiko looks strikingly young for Momo’s grandmother. Her long white hair rises into a towering updo, and she wears red-framed rectangular glasses and large hoop earrings. Her casual outfits include a blue-and-white jacket over a yellow top; a baseball bat and a cigarette are recurring parts of her tough-looking design. Her clothing changes with the occasion, including her work as a spirit medium.

Quick facts

Japanese name: 綾瀬星子
Family role: Momo Ayase's grandmother and guardian
Occupation: Spirit medium; publicly known as Santa Dodoria
Notable protection: Barrier around the Ayase home
Anime voice actor (Japanese): Nana Mizuki

Abilities

Spiritual barriers and wards

Seiko uses ritual protections to defend her home from hostile supernatural intrusions and to restrain dangerous spirits.

Limitations: Her techniques depend on preparation and, for some applications, on power borrowed from a local guardian deity; they should not be treated as unrestricted everywhere.

Exorcism and occult knowledge

She recognizes curses and yokai-related danger and can advise or intervene when Momo and her companions encounter spiritual threats.

Limitations: Not every possession can be immediately undone; some cases resist her attempts to exorcise them.

Ritual preparation and practical guidance

Seiko prepares protections, supervises responses to supernatural problems, and guides younger people whose own abilities are still developing.

Physical combat and improvised defense

Alongside her ritual skills, Seiko is willing to confront threats directly and is shown fighting rather than relying entirely on instructions from a safe distance.

Relationships

Momo Ayase

Granddaughter

Seiko is Momo's grandmother and guardian. Their arguments can be loud, but Seiko's protection, practical instruction, and everyday care anchor the relationship.

Ken Takakura (Okarun)

Momo's friend and a young person she advises

Seiko helps him through the early Turbo Granny curse and encourages him to repay help through kindness toward others rather than money.

Turbo Granny

Former supernatural opponent and household companion

Seiko initially opposes the spirit threatening Okarun; later, their interactions include sharp exchanges and an unexpectedly domestic familiarity.

Jin Enjoji (Jiji)

Momo's childhood friend whom she assists

Jiji turns to Seiko for help with supernatural troubles. She recognizes the need for careful spiritual intervention rather than treating his predicament as an ordinary household problem.

Manjiro

Pupil and shrine priest ally

Manjiro tends the Tsuchinoko Shrine and studies under Seiko. She calls on him to assist Momo and her friends when supernatural trouble reaches his area.

Interesting facts

When Momo was little, the protective gestures Seiko taught her drew mockery from other children.

That childhood embarrassment helps explain why Momo initially rejected Seiko’s spiritual teachings, despite depending on them later.

Seiko makes public appearances as a professional medium under her stage name.

Her television-facing work contrasts with the private, much more dangerous spiritual crises she handles for Momo and her friends.

Seiko's household hospitality extends to the formerly hostile Turbo Granny, with food and even ordinary outings becoming part of their odd coexistence.

That comic domesticity adds a surprising contrast to their original supernatural confrontation.

Frequently asked questions

Who is Seiko Ayase in Dandadan?

Seiko is Momo Ayase's grandmother, a spirit medium, and one of the younger characters' most experienced advisers during supernatural emergencies.

Is Seiko really Momo's grandmother?

Yes. The story explicitly identifies her as Momo's grandmother, despite Seiko's strikingly youthful appearance.

What is Seiko Ayase's spiritual name?

She works as a spirit medium under the pseudonym Santa Dodoria.

How does Seiko protect her home?

She maintains a spiritual barrier and uses protective ritual techniques against hostile supernatural forces.

Are Seiko's powers effective everywhere?

No. Her use of borrowed local spiritual power has geographic restrictions, so location and preparation matter.

Does Seiko help Okarun?

Yes. She intervenes when Turbo Granny's curse endangers him and advises Momo and Okarun as they try to deal with it.

Who voices Seiko in Japanese?

Nana Mizuki voices Seiko in the Dandadan anime.

Major story spoilers below.

The Evil Eye and the limits of exorcism

When Jiji becomes possessed by the Evil Eye, Seiko helps the group try to contain the danger. Yet even her attempted exorcism cannot remove the possession. The others must keep watch over Jiji and look for a more lasting solution, showing that Seiko’s expertise has real limits.

Helping with Rin's burden

Later, Seiko joins efforts to deal with the Onbusuman haunting Rin Sawaki. This moves her from advising the core group into coordinating a more complicated spiritual intervention involving another young person's traumatic attachment.

A new crisis around Momo

After Momo is reduced to an unnatural size, Seiko seeks advice from occult acquaintances about restoring her. The consultation turns violent when a horde of kung fu zombies attacks. Payase and Kashimoto join Seiko against the attackers, turning an attempt to find answers into another fight for survival.

The journey to Shimane

Seiko accompanies efforts to restore Momo, including a dangerous journey that becomes entangled with renewed threats from the Kito family. In the Shimane conflict she is badly injured, and Momo prioritizes getting her to medical care. Momo's size is eventually restored, but the aftermath brings a separate crisis when she no longer recognizes parts of her recent life; Seiko learns of that loss while recovering in the hospital.

New enemies, old responsibilities

Seiko later consults senior spiritual practitioners about the widening conflict. Their discussion identifies the Black Paladins as a dangerous group targeting supernatural powers. Rather than acting alone, Seiko draws on a wider circle of experienced practitioners as threats to Momo and her companions continue to develop.

Spoiler questions

Can Seiko simply exorcise the Evil Eye from Jiji?

No. Seiko attempts to exorcise the Evil Eye from Jiji, but the possession persists. The group must keep him under watch while searching for another solution.

Why does Seiko consult other occult experts later in the story?

Momo's unnatural change in size exceeds what Seiko can immediately solve herself, prompting her to seek help; the search exposes Seiko to another dangerous confrontation.

What happens to Seiko during the Shimane trip?

Seiko is seriously injured during the Shimane conflict and receives hospital treatment. She is overjoyed when Momo returns to her usual size, but the reunion reveals that Momo no longer remembers Jiji or some of their shared experiences.

Has Seiko's entire story reached a confirmed ending?

No. Dandadan is still ongoing, so Seiko’s story has no established final ending.

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