the Akashi Units are members of the Zenin clan who have cursed techniques, but do not meet the requirements for joining the Hei the cursed technique is to make poeple walk in 24 frames per seconds there is another cursed technique that Megumi Fushiguro has aka ten shadows technique but he isn't fighting you right now, and the Kukuru is a lower branch of the Hei comprised of Zenin male members who don't possess innate techniques the hei is the strongest out of the units above semigrade1 by Naoya