This work comes from the master of the world of hentai anime, Teruaki Murakami, and is the first part of the OVA adaptation of Nightmare x Deathscythe: Resonance of Rebellion from Guilty Nightmare Project!
Hasshaku-san... She only appears in front of cute men, ready to wring them dry, wearing a white hat and a one-piece to match. Watch this mysterious being help boys turn into men.