Battle Spirits: Ryuuko no Ken

Synopsis

Martial artist Ryo Sakazaki and his wealthy friend Robert Garcia accidentally stumble into a jewel thief's apartment while attempting a cat rescue. They witness a murder and escape, only to discover the perpetrators work for the notorious crime boss, Mr. Big. Falsely accused of stealing a valuable diamond and with Ryo's sister Yuri kidnapped, the duo must confront Mr. Big's forces to recover the gem and rescue Yuri before time runs out.