arachnid (series)

A 2009 manga written by Murata Shinya, illustrated by Ifuji Shinsen, and serialized on Gangan Joker. It follows the adventures of Fujii Alice, a girl who is trained to use a concentration disorder to her advantage as a spider-themed assassin. It's notable for battle narrations that compare the characters' abilities to the behavior of insects, sometimes to a rather nonsensical effect.

It has a spinoff storyline named Caterpillar which serves as a prequel and features a woman named Imomushi, who is a member of the assassin organization that will later target Alice.