In 1935, Kitahara founded "Tama", a "tanka" magazine, and became known as the spearhead of the fourth stage of the symbolist movement. Among his protégés were Kimata Osamu and Miya Shuji. He also accepted an invitation by the Osaka Mainichi Shimbun to tour Korea (then under Japanese rule), in exchange for poems on his impressions. Kitahara remained active even after almost going blind due to complications arising from diabetes in 1937. In 1940, he returned for a visit to Yanagawa after many years, and also visited Miyazaki and Nara. That same year he was made a member of the Japan Art Academy. In 1942, his health condition worsened, and he died of complications from his diabetes. His grave is located at the Tama Reien in the outskirts of Tokyo.