Masked Rider Kabuto / Kamen Rider Kabuto (1-49 end), Anime TV Series.
Kamen Rider Kabuto revolves around the story of a man named Tendou Souji. He has trained his entire life while waiting for the Kabuto Zecter so that he may properly take up the name of Kamen Rider Kabuto. Making many enemies while at the same time meeting other Riders with mysterious origins, Tendou attempts to accomplish his goal at all costs; Protecting Hiyori by destroying all other Worms that would make life difficult for her. Making a friend in Kagami Arata, who later becomes Kamen Rider Gatack, the two work together and protect Hiyori along with humanity from the alien Worms that arrived from a meteorite seven years ago.