Manzo Iwata was born in Tokyo, Japan, to a family that owned the Iwata-en Tea Company.

After graduating from Toyo University in 1944, Iwata also received a Shihan diploma from Mabuni.

[3] After the death of Fujita in 1966, Iwata became heir to many of his styles, but not of Kōga-ryū Wada Ha Ninjutsu.

In 1960, Iwata established the Nihon Karate-Do Kai Eastern Japan and became its first president.

In 1980, he became the president of Shito-Kai, and in 1993 received the Japan Martial Arts Distinguished Service Medal.