From the Animeraider:

A young man named Sudou has come to the Rikugun Nakano Academy to study, having been sent by his grandfather at the invitation of the Hanamoto family patriarch. One problem - it no longer exists and is now a private residence of the Hanamoto family - the moderately senile grandfather, his grandson Kentarou and granddaughter Takeshi (you read that right - Takeshi) and a dog named Kobayashi Maru.

To give you the tone - the dog checks his water dish for poison. Sudou gets arrested for showing his martial arts prowess. The grandfather sometimes thinks that Sudou is his grandfather, whom he served inthe army with before World War II. And don't even get me started on a girl named Takeshi. Lots of parody and bad puns to go around.

Silly, fun stuff.