Mrs. Tendo

Mrs. Tendo is the unnamed mother of Akane, Nabiki, and Kasumi, and the wife of Soun. She died an unexplained death when Akane was very young. Mrs. Tendo remains a hard subject for the Tendo family, especially for Soun, who still mourns, remains loyal to, and regularly prays for her, though when given compassion by Hinako Ninomiya he was able to joke about it to relieve the tension. Out of the girls, Kasumi seems to have handled it best and was able talk to her grave in a relaxed manner and "tell her" that everyone was doing fine. Akane likewise seems to have handled it quite well, but is fiercely opposed to anyone taking her place, while Nabiki seems to have bottled it up as an unwanted sentimental "weakness" which once managed to overwhelm her, and thus she may consider Nodoka Saotome as a surrogate.

One of the few things known about Mrs. Tendo is that she kept a detailed diary of meals she made and the recipes she used to make them, which Kasumi used to emulate her cooking after her death. She was also shown to have been a kind and nurturing mother to the young Akane, and comforted her when she was sad over accidentally breaking a carnation intended as a Mother's Day present. Though her appearance was never shown or described in the manga, there were a few anime flashbacks that were filler which showed she resembled Nodoka except with sky blue colored hair.

Trivia

 * Mrs. Tendo bares some similarity to Kagome's mother, Mama Higurashi, from Rumiko Takahashi's series after Ranma ½, InuYasha.
 * Coincidentally both characters where voiced by Cathy Weseluck in their respective english dubs.