is a name given to a group of three famous Chinese calligraphers who lived in Japan:
Ingen Ryūki, 隱元隆琦 1592–1673 Mokuan Shōtō,木庵性瑫 1611–1684 Sokuhi Nyoitsu, 即非如一 1616–1671
They are all connected with the Ōbaku school of Zen Buddhism. Analogous groups of famous calligraphers include the Sanseki and Sanpitsu.