Banzai, by John Paris, New York: Boni and Liveright. $2.50. The author, at one time attached to the British embassy in Tokyo and writing under the name of John Paris, knows well certain phases of Japanese life. In Banzai he indicates his familiarity with geisha and yoshiwara problems, with student life and restaurants. But Banzai is much more trivial than the author’s previous novels of Japanese life, Kimono and Sayonara.