Tatsumaki Takeru was the son of a great hero. His parents were killed in action during a fight with a dangerous villian and leaving him all alone. This is a story where he become one of the greatest hero ever. All he have with him is his older sister. But still doesn't know that if it's true that his parents was killed. This is a first time I combine Kamen Rider and anime. Only Kamen Rider Build and his side character kamen rider will be fully appear. Other Kamen Rider only the main character and side rider. I follow the story from the anime and add some of my own.