The show opens upon a ball that Sandman had thrown to unveil the Gravion project. It is during this that the first Zeravaier attack occurs and the commanders of the Earth government realize how much power Sandman could wield. This of course generates a large amount of resentment towards the handsome trillionaire (as is human nature).
Sandman is not orignially from Earth, but from a remote corner planet of the galaxy that no longer exists. Ergo, it was destroyed. Sandman had built a functioning version of Gravion and proposed to the people of the planet to use it for defence. This was overruled by Sandman's own brother, who ironically is the perpetrator of the entire Zeravaier problem. Once Zieg (Sandman's brother) calls the Zeravaier down on the planet Sandman jumps into the cockpit of his Gravion and attempts to fight all of the Zeravaier by himself. Of course, he fails to destroy enough of them to stop the destruction of his home planet. Determined to stop Zieg from doing the same to another planet, Sandman goes to Earth, building a multi billion dollar industry out of almost nothing inside the span of a few years. While doing this he secretly built the Gravion used by the team, the Sol Gravion that is unveiled later, and a powerful sword called the White Steel Fang. All of them under direct voice control from him.
Sandman keeps the secret of Aiaka's dissapearence from the others, in part because she never went anywhere at all, and in part because he loved her and was doing as she asked.
Aiaka had taken the guise of Raven, Sandman's assistant, and is only revealed as her ture self when she removes Raven's mask (changing from a built guy to an extremely busty woman, maybe even more well endowed than Mizuki, which is just scary, just by removing a mask... creepy). Aiaka is then forced to drag Sandman out of the first of his gloomy moments. Somthing that happens a lot towards the end of the second season. Sandman gets depressed when somthing exceptionally bad happens to the people under his command.
Once he kills Zieg Sandman was going to let himself die along with his brother, but Aiaka and the others convince him that he still had a lot to live for.
Sandman is... politely put, very quirky. He has a lot of random moments. As in one instance, when he usually announces Gravion's enterance into battle, he adds onto the end of the repeated phrase, "a heavy metal god!!!" When the others in the command center turn to look at him he smiles and says, "I've always wanted to say that." Completely random. He is also somwhat of an opportunist, as when a Zeravaier attack brings them all to Okinawa (not sure if I spelled that right) he gives the Gravion team a short vacation on the beach. He even joins them, eliciting a positive (in a flirty way) comment from Mizuki about his speedo. Another odd moment is at the company vacation to a hot spring. Scenario, Mizuki and a random guy were competing with the others for an extended stay at the hot spring. Sandman enters the competion with Leele, who has never so much as touched a ping pong (the competition) ball in her entire life. Sandman derisivly tosses aside the paddle and takes off one of his slippers, giving the other to Leele, and starts to absolutly demolish Mizuki and her temporary fling. Sandman is so good at the game that Mizuki and her beau don't even score a single point. One time Sandman even hit the plastic ball so hard it went right through the paddle of Mizuki's beau's paddle, knocking the other guy out cold.