Original Kamen Rider: Kamen Rider Walker

【Original Riders + Original Worldbuilding + Battle Royale Game + Female Protagonist, Though It Could Also Be Called an Ensemble Drama】 (ps: The Riders in this story are also known as Music Armor, and the story follows a TV-series style.) Forty years ago, monsters from another dimension invaded the real world. Six Kamen Riders fought back, and only by sacrificing themselves along with their enemies did they avert the crisis. Afterward, the six Drivers vanished without a trace. Forty years later, the conspiracy has resurfaced. The original Drivers have been copied and turned into tools for a deadly game. Threatened by both malicious players and awakened monsters, Tang Jiayao must recover the six missing Drivers to stop the disaster that is about to unfold.