Ero Ninja Scrolls manga volume 5 features story and art by Haruki.

Sexual ninja Arakusa has been kidnapped and is being held hostage onboard one of the Black Ships! It’s another typically desperate situation made worse when her Western enemy displays his mastery of jutsu! Arakusa’s pupil Tokuta and her senpai Sari rush to rescue her but are waylaid by a mysterious woman brandishing a special “toy.” Will Tokuta and Sari get to Arakusa in time, and if so…in time for what?!