>>1964999Long story short, Gridman and Ultraman are made by the same company. Gridman was essentially a spiritual spinoff of Ultraman in the 90s, where Gridman fought inside cyberspace instead of real life like Ultraman because its the 90s and the internet exists now. It wasn't that popular. Gridman was actually brought to the US as Superhuman Samurai Syber Squad, hence the SSSS in the title.
Trigger, for some reason, revived the dead Gridman name in like 2015 for a short at a convention, and made it into a full show later. and that takes us to SSSS Dynazenon which is a sequel/spinoff of that anime