If you never read any 4 panel gag manga. Read this masterpiece. For me, this is the face of four panel gag manga.

Story
It pictures an everyday life of school girls and their teachers in an unnamed Japanese high school. Yes, it is so simple and that is the beauty of it.

Art
Its a four panel gag manga. So, the art is not that great but it suits the story and the format of the manga. In another word it's perfect.

Character
One word for all the characters in this manga: IMAGINABLE
Its not the story. Its not the art. Its the character that makes me fall in love with this manga.
That is 20 words. hehe.

Enjoyment
Its very enjoyable. It is very impressive how the author pull out so many comedies out of that simple plot.

Overall
The story is plain, the art is good, and the rich set of characters (especially Chiyo, Chiyo is very rich) make this manga very enjoyable and super duper fantastic. Read it you'll understand.