Chao was offered a full-time role on Deep Space Nine, which she turned down because the demands on her would be too strenuous. Keiko instead appears irregularly, with a focus on the impact of Miles’s job on the O'Briens' relationship. Finding limited opportunity to use her botanical expertise, and concerned about the educational opportunities on the station for her daughter and others' children, she starts a school, where Jake Sisko and Nog are also students.
