I recently read that there's a character called "Golden Bat" or "Ogon/Ohgon Bat" who is commonly regarded as the "oldest Japanese superhero." When did he first come on the scene?
According to this site, Golden Bat started out something like American pulp heroes, but gradually lost much of his original paraphernalia and appearance. In the 1960s, he had a revival with his own schlocky live action tokusatsu-style film (a snarky but affectionate review of a subtitled version of it can be found here)...
...which was followed up the next year by an anime.
I have to admit, the idea of a heroic character who responds to "we're gonna start killing hostages!!" by starting to blow away the guys who are shoving them off the giant squid drill thing (starting at 4:32) and who also laughs like Dracula amuses me pretty badly.
He's also invincible, can fly, and can shoot lasers from his cane/baton thing.
I also must admit that I find the villain, "Nazo," pretty visually fascinating for being a creature with four eyes and heterochromia (even if he does look like a guy in a cheap hamster suit in the film version).
Amazingly, the character somehow failed to have a revival in 2000, but this failed revival has left behind a tantalizing internet trailer that can still be found on YouTube.
The character is internationally famous in a number of non-English-speaking countries under names such as "Fantaman" and "Phantasma," basically anything that sounds vaguely reminiscent of
I don't think I could possibly find this guy more entertaining, really.