|School||Hiiragi Academy's "Ichou" Branch Campus|
|Manga Debut||Chapter 16|
|Japanese Voice Actor||Ayane Sakura|
|English Voice Actor||Apphia Yu|
Sachiko Tanaka (田中 さち子 Tanaka Sachiko) is a character in Denpa Kyoushi. She was truant student of Kagami's who didn't go to school so she can work as a mangaka under the pen name "Kisaki Tenjouin".
Tanaka has long blond hair and red eyes. She is fairly short with fair skin and often wears either her black frilly dress or the school uniform.
Tanaka is a rather apathetic and laid-back and seems to only really care about her fans. However, she does care about her other classmates at times, although her and the student council president, Makina Momozono, don't seem to be on very good terms.
Junichirou calls her "Kisaki-sensei" and is a fan of her manga "Shuumatsu Gakuen", even calling it a masterpiece. Her previous manga was called "Hanauta" and was supposedly very popular until the magazine ceased publication. As such, the last chapter was never published.
A famous mangaka under the pen-name Tenjouin Kisaki, and a childhood friend of Momozono. She turns out to be one of the two truant students from Junichirou’s homeroom who has yet to attend class, and was even held back a grade at Ichou Academy due to her continued work on her manga, Shuumatsu Gakuen.
To get Tanaka to return to school, Junichirou establishes a deal to have her attend school to “observe” the student council president for data as she goes about her duties, much to Momozono’s chagrin. Momozono eventually caves to being observed for manga material, but only if Tanaka returns to school full-time. For the smooth transition into school, Junichirou decides to turn his classroom into Tanaka’s office; even getting his students involved in helping with the development of the next chapter.
She is now seen attending Ichou full-time; playing a part in encouraging her fellow truant classmate, Koutarou, to return to attending school, and even befriends a wayward ghost, Matome, into getting some closure. She then unintentionally becomes one of the candidates for Junichirou’s SS group war against the main campus; much to her confusion as she was trying instead to sponsor Momozono to be a candidate, and ends up getting chosen as one of the five students.
Now a member of Junichirou's team Silver Core, she participates in the soccer match against team Titan.
- Sachiko's surname Tanaka means "field, rice paddy" (田) (ta) and "middle" (中) (naka).