Rinzai (臨済) is one sect of Zen as well as Soto.
Lin-Chi was the founder of the Rinzai sect of Zen Buddhism. Rinzai's style of teaching was characterized by harsh encounters; punching, kicking, hitting, etc. His sayings were collected into the Rinzai Roku (Record of Rinzai) by his students.
The Rinzai school has historically been closely linked to various martial-arts traditions in Japan, China, and Korea. In pre-modern Japan, Rinzai was widely popular among the warrior aristocracy and samurai, in distinction from Soto Zen which was more associated with artists and poets.