Caterpillar

Caterpillar is a seinen spin-off of manga Arachnid written by MURATA Shinya and illustrated by SAYAZAKI Isuka.

Plot
Possessing both flexibility and tenacity, Imomushi (Japanese for Caterpillar) is an assassin that does not kill anyone but those who are assigned to her. She seems to have had something happen between her and her older sister in the past, however.