Sensei no Ojikan: Dokidoki School Hours OVA
Genres: Comedy
Type: OVA, Episodes: 7
Aired: Aug 4, 2004 to Feb 2, 2005
Studio: J.C.Staff
Source: 4-koma manga
Rating: PG-13 - Teens 13 or older
Synopsis:
The series is centered on 27-year-old homeroom teacher Mika Suzuki (who only looks about half her age) and the eccentric and colorful students of her class. 

(Source: Wikipedia)