Shihan Shajan Jacob was born on January 15, 1967. He started learning karate in 1982 at Kattappana under Sensei K Kumarasami and Sensei Rajashekaran from Madurai. Thereafter he continued his learning under Sensei Mosses Thilak, Sensei Manoharan, Sensei Jacob in Madras.

He received Black Belt in 1986 from Sensei Moses Thilak and became the member of State Karate team in 1987. He participated in AIKF tournament held in Maharashtra in 1987 and was awarded AIKF Shodan from there.

Bagging Gold and Silver medals in weight and open categories of kumite in 1985 State Level Karate Championship held in Kollam, he became the Champion. He received Bronze medal in 1990 National Championship held at Antheri in Maharashtra. He was present in SokeKeniMabuni at Kochi in 1989. In ShitoRyu National Championship he got Gold medal. Then he turned to teach karate. Currently being the Indian Chief for International Seishin Ryu Karate Federation (ISKF) and taking classes in this style of karate all over Kerala.