Tsukasa Kadoya is the main protagonist of Kamen Rider Decade, a Japanese tokusatsu series. As Kamen Rider Decade, Tsukasa possesses the ability to transform into the Riders from previous series, allowing him to travel between various parallel worlds. His journey centers around restoring balance to these worlds, which are in danger of being destroyed. Tsukasa is enigmatic, confident, and sometimes aloof, but gradually shows more empathy and resolve as he discovers his true origins and purpose.