Although Seishu Hanaoka glories in the history of anesthesia in Japan, misunderstandings of his medicine and philosophy are widespread among the public as well as physicians. The incorrect opinions include: 1) he kept his art under wraps, 2) therefore his medicine did not prevail through the country, 3) the general anesthetic that he developed was formally called Tsu- sensan but not Mafutsusan, 4) his surgical art was too transcendent to be learned by his disciples, and 5) erroneous views of Seishu's maxim Naigai Goitsu Ka- tsubutsu Kyuri. Teachers of anesthesiology in any edu- cational institution are required to have correct under- standings of these subjects because the name of Hana- oka is well known among foreign anesthesiologists and they have much interests in his medicine and philoso- phy.