This training method is done by placing a leaf over an individual's forehead and having them direct all their chakra onto the leaf, using it as a focal point.
This exercise can be used by Academy teachers as a way to teach students how to control their chakra more effectively. However, the true purpose of the exercise is actually to hone the individual's concentration and to keep their mind from becoming distracted. As explained by Iruka Umino, only those who have worked hard on their ability to concentrate can become excellent shinobi. For generations Konoha ninja have practised using this method in order to better their mental focus. The leaf emblem on the Konoha forehead protector is said to originate from this training.
- While trying to master the Rasengan, Naruto thinks back to this lesson, and uses Iruka's advice to complete the second stage of the ninjutsu.