Top wo Nerae! Kagaku Kouza
English name: Gunbuster! Science Lesson
Genres: Comedy, Sci-Fi
Type: Special, Episodes: 6
Aired: Oct 7, 1988 to Sep 18, 1995
Studio: Gainax
Source: Original
Rating: G - All Ages
Synopsis:
The science lessons are short "omake" bonus features originally present on the first two volumes. Each short lasts around two minutes, and stars super deformed versions of Noriko, Kazumi and the Coach explaining the various scientific aspects of the series. 

(Source: Wikipedia)