The first Kamen Rider who awed every Japanese was seen as early as April of 1971. After the success of the first Kamen Rider Series - Kamen Rider V1 and V2 (1971) it has gave birth to eight more Kamen Rider series: V3 (1973), X (1974), Amazon (1974), Stronger (1975), Skyrider (1979), Super-1 (1980), Black (1987), and Black RX (1988). These are the Kamen Riders of the Showa Era which ran from 1971 to 1981.
The Kamen Rider Series lived through the 90s through merchandise and toys, until the rebirth of the new Kamen Rider Series which is now under the Heisei Era. The Kamen Riders of this Era are as follows: Kuuga (2000), Agito (2001), Ryuuki (2002), 555 (2003), Blade (2004), Hibiki (2005), Kabuto (2006), Den-O (2007), Kiva (2008) and now to celebrate the 10th Anniversary of the Heisei Era Kamen Rider series, Kamen Rider Decade was born.
So far the story revolves around Tsukasa Kadoya and his question of how and where does he truly belongs which later vividly shown to him that he is Decade, the destroyer of the nine other Kamen Rider Worlds (starting from the Heisei Area) to save all the worlds. He later travels from world to world trying to figure out how he will save his world and the rest; and collect all his lost powers and memory.
He has the ability to use and transform into other Kamen Riders and their powers. He can also transform the previous Kamen Riders into weapons which is somewhat making an issue to previous fans for the injustice it is somewhat making but so far this hasn't affected the show and it is all great reviews majorly. There is more to see and expect the story unfold in the next episodes.
Watch Kamen Rider Decade opening theme here: