Although the H-I did have some domestically produced components, such as LE-5 engine on the second stage and inertial guidance system, the most crucial part, the first stage engine, was a licence-built version of the Thor-ELT of the US.
Although the H-I did possess some domestically manufactured components, such as the LE-5 engine on the second stage and inertial guidance system, the most vital part, the first stage engine, was a licensed version of the Thor-ELT from the US.