Fumoffu is the 2nd series of Full Metal Panic. Unlike the first series which is somewhat serious and the 3rd which is a bit dark, Fumoffu has no villains, all-comedy and watching the characters in the story fail, get into unnecessary situations and use extraordinary methods to achieve something.
I believe it was a pretty heartwarming series considering what the protagonist have to go through later on. In addition, you get to see Fumoffu(although Sasuke in disguise) into action. A stuff animal running around causing rampage is a good way to cause some laughs. In a sense, this this Sasuke changing the world around him even though methods can be a bit extreme at times.
It is a pretty enjoyable series. Nothing but to say, except it will be a relief pill the moment you go to the 3rd and final series of FMP.......