Seiko Ayase

Seiko has a phlegmatic personality and a highly uncouth manner of speech. At the same time, she is selfless and empathetic to help others in need if it's within her power, with the greatest example being her taking people into her house if they need a place to stay. As such, she follows the concept of "being in it together". Instead of accepting Okarun's generous compensation for looking after him while he was cursed by the Turbo Granny, Seiko told him that the only way he could repay her was to help other people who were in trouble. When involving herself with children, Seiko believes that, as an adult, she should be able to shoulder their burdens to allow them to be free to do what they want in life. Because of this, she felt saddened that she was unable to honor Jiji's wishes to help him keep the Evil Eye under control in order to spare the yokai from being exorcised. While willing to help others, Seiko is too proud to admit when she needs help herself or burden others with her problems, having at first refused Okarun and Mr. Mantis Shrimp's offer to help rebuild her house when it was in ruins after the Evil Eye's stay.

Seiko can also come off as being a bit immature, such times being when she joked about Momo having a crush on Okarun, due to him having the same name as Ken Takakura, and having her granddaughter make a Hiroshi Abe impression in exchange for having to buy her a new school uniform. Despite this and her unladylike way of speaking, Seiko can act polite if she feels that she has made a mistake that involves the well-being of others. This side of Seiko is seen as being rare and out of character to those who know her well. Though she claims that she has never been moved by emotion, Seiko subconsciously favors those who compliment her, such as her youthful appearance which she takes great pride in.

As a spirit medium, Seiko follows the rules of coexistence between the living and the dead, which is to not disrespect the dead and send them to the afterlife, by using force if necessary, if they choose to attack the living.

Seiko has a passion for food, believing that it should not be taken lightly since "living begins with eating". As a cook who occasionally serves food for Momo and her acquittances, she finds it delightful to see a person who knows how to eat by filling up on the food she makes and even becomes motivated to make more to further satisfy their appetite. She was even willing to feed a restaurant full of Renjaku High School student at the cost of her entire paycheck. On the other hand, she dislikes picky eaters.

While a believer in spirits, Seiko is a disbeliever in UFOs or aliens. Even after Momo brought home Mr. Mantis Shrimp as proof, Seiko only saw him as being a kappa and did not think much of the alien's spacecraft after abducting a cow. She enjoys watching television shows, which is the only thing that brings her a sense of joy and laughter in life.