Apparently I was wrong, I stand corrected.

Here's a list of various Japanese launch systems and their success rates.

System - success - fail - percent success

- Epsilon - 1 - 1 - 100%

- GX - 0 - 0 - (abandoned)

- H-1 - 9 - 9 - 100%

- H-2 - 5 - 1 - 80% (or 60%, one of the successes was a partial failure)

- H-IIA - 23 - 1 - 95.7%

- H-IIB - 4 - 4 - 100%

- J-I - 1 - 1 - 100% (then abandoned)

- Lambda 4 - 9 - 5 - 44%

- Lambda 4S - 5 - 4 - 20%

- M-V - 7 - 1 - 85%

- N-I - 7 - 1 - 85%

- N-II - 8 - 0 - 100%