Choubu no Shinobi

Choubu no Shinobi (蝶撫の忍) is a manga series written by Murata Shinya and illustrated by Hayami Tokisada.

Plot
One year after the death of Oda Nobunaga, a ninja codenamed Tiger Beetle readies himself to finally fulfill his most important dream, one that many of his comrades died unable to realize: getting laid. However, once he enters a brothel he instead gets caught in a conflict between two ninja clans who are hunting Rin, a female assassin with butterfly superpowers who took Nobunaga's head.