Complex sentence: She is very clumsy and an otaku when it comes to guns, tanks, etc. (basically anything that has to do with military equipment), so most of her classmates, except for Asao, would ignore her.
Split into simpler sentences: She is very clumsy, but enjoys playing with guns, tanks, and basically anything that has to do with military equipment. Most of her classmates, except for Asao, would ignore her.