Rinzai Zen traces itself to the Chinese master Linji Yixuan and was brought to Japan by Eisai and others. Reformed by Hakuin in the eighteenth century, it uses a graded system of kōans under close guidance of a teacher, aiming at kenshō and its deepening.
Rinzai
The Japanese Zen school descended from Linji, known for kōan practice and sudden awakening.
Also: Linji