Mikami-Sensei

Mikami-Sensei is the vice homeroom (assistance) teacher of 9th Grade Class 3 at Yomiyama North Middle School.

Personality
She is described as a beautiful teacher and was dubbed the 'killer type'. Many students wanted her to be their homeroom teacher instead of Kubodera-Sensei.

Appearance
In the anime, she has long brown hair that is slightly wavy. In the manga, she has black hair and wears spectacles.

Plot
Although not immediatly obvious, Ms. Mikami and Reiko are the same person, and Sakakibara just behaves differently around them whether they're at school or home.

She is the "dead person" for the year, and the source of the calamity in 1998, having originally died in 1996 due to drowning.