Answer
In Japan, the first Zen monastic code, the Shōbōgenzō, was written by Eihei Dōgen, a revered Japanese Zen master and founder of the Sōtō school of Zen Buddhism in the 13th century. It encapsulates the essential teachings and practices of Zen, covering topics such as zazen (seated meditation), koans (thought-provoking questions), and enlightenment.