Hokkezanmai is a Hangyo hanza sanmai (religious austerities with concentration, which combines a standing-style one and a sitting-style one), one of Shishuzanmai (the Four kinds of samadhi) in Tendai-shu sect, that is based on Hoke-kyo Sutra and performed for 37 days.
法華三昧は、天台宗における四種三昧の1つである半行半坐三昧のうち、法華経に基づいて行われるもので37日間行われる行である。