Kotoko Fujioka (née Katayama) was Haruhi Fujioka's mother, who died while her daughter was approximately five years old (four years old in the manga), based upon Haruhi's remark at the beginning of the series that ten years had passed since Kotoko's death. It is known that she was a fine attorney who remains a role model for her daughter, who takes after her in both brains and beauty.
When she was alive, Kotoko was a loving wife and mother, as well as a fine attorney-at-law. One may also assume that she was a tolerant and open-minded individual, as she accepted Ryoji's career choice and bisexual orientation without hesitation.
Kotoko is said to have been very intelligent, sweet and caring and that she wished nothing but the best for her family. She was also said to be a good cook. Kotoko is an alumna of St. Lobelia's and former Zuka Club fan, as revealed by Ryoji in Ep 19 - Lobelia Girls’ Academy Strikes Back! Her teachers and peers recognized her talent and expected her to become an elite, but Kotoko decided to take a small-time, altruistic job helping local citizens instead. After graduating, she also gave numerous speeches at her law school. Kouhai Yuko Kosaka, though she admired Kotoko's talent, saw her disconcern with money as a luxury of choice.
Kotoko met Ryoji while he was working as a bartender, and he provided the winning testimony in her first court case. He fell in love after witnessing her talent as a lawyer and broke off his affair with a married man to be with her. At first, she found him to be annoying, but their relationship developed after Ryoji saved her from an enraged person in a public park. Kotoko was flattered that he cared so much about her safety and Ryoji was further smitten when it turned out that she could've easily defended herself with her karate skills. They began dating when she was 25 and he was 19. Their wedding was described as a "shotgun wedding" and many friends and family members disapproved of their romance.
Kotoko's is mentioned by Haruhi in Ep 01 - Starting Today, You are a Host! and "seen" in Ep 10 - A Day in the Life of the Fujioka Family! where her memory appears in Haruhi's mind as she is best remembered - in her work suit, telling Haruhi that's she going to win her current legal case and holding up two fingers in a "peace sign." Kotoko is actually speaks as a character in Ep 13 - Haruhi in Wonderland! in which she plays the role of the masked Queen. With the exception of the final scene, the entire episode is a dream-state wherein Haruhi explores her "place" at Ouran and is provoked into expressing some of her deepest still-held sorrow over her mother's death.