The Sakuragaoka Laboratory continued to create a string of hits starting with its 1938 launch of Japan's first commercial vitamin E product Juvela, which was developed from wheat germ oil extract. Juvela was closely followed by other successes such as the sanitary tampon Sampon and La Vende, a medicated talcum powder. At this point, the Sakuragaoka Laboratory research team had swelled to 74 members and outgrown its Tokyo facility. To expand further, Toyoji purchased the Tsurumaki Silk Mill just north of Tokyo in Honjo, Saitama, and on December 6, 1941, established Nihon Eisai Co., Ltd.—Eisai's second incarnation—with ¥180,000 in capital. In just two days, the Pacific War would begin. Toyoji was 53 years old.
In May 1942, the Japanese government issued a public declaration under its wartime national policy, enforcing industrial adjustments aimed at streamlining Japanese industry. Under the legislation, all companies with ¥500,000 or less in capital were to be either consolidated or closed down. Accordingly, Sakuragaoka Laboratory Co., Ltd. and Nihon Eisai Co., Ltd. were merged together on December 26, 1944, with the new company retaining the name of the latter—Nihon Eisai Co., Ltd.