Omori was born in Fukasima, Japan. She began her dance studies when she was 4 at the Susuki Ballet Academy. When she was 17 years old she was accepted to the Royal Ballet School of Flanders (Belgium)

She has been coached by Kazuko Suzuki, Toru Shimazaki, Etuko Sumii, Eva moreno, Maria Metchkarva, Yen Stolk, Anotole Karpuhin, Etienne de Canne, Michele Swennen, Rovert Denvers, Stephen Jeffrys, Rashna Homji, Wong Jo-Hong, Tang xiu-yun or Patricia Llington, between others.

In 2000, Kazuko danced with the Flanders Royal Ballet, where she remained for one year before joining the Hong Kong Ballet in 2001, where she danced for 3 years and broadened her classical repertoire. In 2006 she joined to the Angel Corella´s touring group with the ABT's stars and in 2008 she became part of the Ángel Corella's Company as first soloist.

Kazuko Omori has won many prizes as: All Japan Ballet competition while still a student of Suzuki Classic Ballet Academy; Silver medal all Japan ballet competition, 1995-96; Finalist 2nd Japan International Ballet and Modern Dance Competition,1996; Semi-Finalist Prix de Lausanne, 1998 and most promising new comer Hong Kong Ballet Dancers Award, 2003

Her repertorie includes: "Sleeping Beauty": Song Bird, Princess Florina, Aurora's Friends; "Nutcracker": Clara, Lead Snow Flaks, Chinese, Spanish, Dance of lead, Fluets, Lead waltz of flowers; "Cinderella" (David Allan): Spring Bird Fairy, jesters, Arabian; "Turandot", "Rite of spring" (Natally Weir); "Last Emperor" (Wayne Eagling); "Beauty and the Beast", "White Snake" (Domy Reiter Soffer); "Coppelia", "Romeo and Juliet" (Bent Jorgan); "Don Quixote pas de deux" and Cupid; "Paquita": Principal, Pas de Trois; "Le Corsarie pas de trois"; "Swan Lake", "Mulan" ,"Tango Ballet Tango", "Great Archer", "Giselle", "Esmeralda", "Flames of Paris", "La Fill mal gardée" (Ame de Ligniere) "La Bayadere", "Raymonda", "The Fire Bird" as Fire Bird (Andree Marliere), "Dream Dance" (Jirl Kylian); Several Toru Shimazaki's contemporary works "Divertimento Concertante (George Birkazde) and many other leading roles of classic and contemporary works.

In 2008 Omori joined the Corella Ballet as First Soloist, her roles with the compnay includes: Nikiya in Makavora's "Bayadère"; Odette/Odile in "Swan Lake"; Pink and Aqua Pas de Deux in "Bruch Violin Concerto"; Medora in "Le Corsaire Suite"; Diana & Acteon Pas de Deux; Don Quixote Pas de Deux; "Walpurgis Night"; First Girl in "Fancy Free"; Main Couple in Corella's "String Sextet"; Quartet in Wheeldon's "VIII"; First Classical Couple "In the Upper Room"; Welch's "Clear"; Tchaikosvky Pas de Deux, Don Quixote Pas de Deux; The Nutcraker Pas de Deux; The Taming of the Shrew Pas de Deux and "Who Cares?".