In

In (隱) is an advanced form of Zetsu that can almost completely hide a Nen-user. In can also be used on a Nen-user's Hatsu ability (more information on why some Hatsu abilities are visible can be found in the Hatsu category section) to make it invisible to other nen users. In can be countered by using Gyō on the eyes, or by using the technique En.