In the clip below, normal Japanese guy transforms into the web-slinging superhero with the help of a metal bracelet kind of like how super sentai heroes like Maskman, Bioman, and Power Rangers do. The clip compiles these transformation segments, lifted from the 1978 show Spider-Man by the Toie Company, the same guys behind the aforementioned super sentai shows. Yes, Batman, once he calls upon the power of the bracelet, the signature blue-and-red Spidey suit drops from above, he zips it up, and voila, Japanese Spider-Man!
And they did just that. In the Marvel canon, Peter Parker was bitten by a radioactive spider. In Toei's world, Peter Parker is Takuya Yamashiro who chances upon a fallen UFO where he discovers the last surviving warrior of Planet Spider. The warrior, named Garia, reveals that his world was destroyed by Professor Monster, who then subsequently transfers spider-like powers to Takuya. He is also given the bracelet that allows him to activate his "spider protector" costume, shoot web-lines, and control the UFO—and get this, a giant mech called the "Leopardon."
It's this one:
To sate your need for more Japanese Spider-Man, here's the show's intro: