Hiroshi has always dreamed about being a superhero. He's been struggling for a while to realize a concept that's been boiling in his head since his college days studying under Professor Amagi. After many failed attempts, he makes a breakthrough. By inputting brainwaves into his computer, he designs a pseudo-molecular suit that gives the user great strength, speed and power. This was made possible by using a rare item called the Mol Crystal as its core.

Now armed with this incredible piece of technology, he decides to make a name for himself by performing many heroic deeds around Tokyo. This earned him the nickname Captain Tokyo. Later on his sister, Mirai Ozora, changes the name to Moldiver.