Kazuko teaches Madoka's class and is basically perpetually single—her relationships never seem to stick around. She's pretty open about her frustrations too, which means her students get an earful about men and dating drama fairly often during lessons. On the friendlier side, she's close with Junko Kaname, Madoka's mom, so there's that connection outside of school.
Content compiled by AnimeList.moe from publicly available sources.