Ozaki Hosai (1885-1926) was a promising and radical Japanese poet, but only produced one volume of haiku during his life.

Hosai met Ogiwara Seisensui while still in high school and began writing haiku. He studied law at Tokyo University and became a branch manager of an insurance company. But he was a drunk, and his career suffered despite his prestigious degree. In 1922, he joined a firm in Korea to reignite his career, but he ended up wandering northern China, where he became ill.

After his return to Japan, he gave up all his belongings and left his wife for the monastic life. He wandered from temple to temple eking out an existence by doing chores as an itinerant handyman. He finally settled down on an island in the Seto Inland Sea, where he caught tuberculosis and died.

Like his friend Seisensui, he abandoned all the traditional rules of writing haiku in favor of "free verse" haiku. While Seisensui and his followers abandoned them out of literary principles and were rebelling against the existing order, critics think that Hosai’s motivations flowed naturally from his free-spirited life style instead of from literary theory.