Koen OTANI studied traditional Japanese painting under Bairei KONO and Seiho TAKEUCHI, was influenced by Shiki MASAOKA and commented on in the magazine "Hototogisu" by Hekigoto KAWAHIGASHI and Kyoshi TAKAHAMA who he admired and looked up to.
幸野楳嶺や竹内栖鳳に日本画を学び、また正岡子規の影響を受け、『ホトトギス(雑誌)』誌にて河東碧梧桐、高浜虚子らに選評してもらい、彼らに傾倒して師と仰いだ。