Rintaro transformed into Kamen Rider Blades. When Mei Sudo greeted Rintaro with a box of éclairs, he revealed his love for sweets. Rintaro demostrates his ability to transform into Kamen Rider Blades and together, he and Saber were able to subdue the Ari and Kirigirisu Megid.

Arriving to his bookstore riding a blue lion, he approched Touma to hand over the Brave Dragon Wonder Ride Book before bringing the novelist to the Northern Base of the Sword of Logos to meet Sophia. Rintaro Shindo arrived to witness Touma Kamiyama, a “Homo Sapien”, transforming into Kamen Rider Saber to vanquish the Golem Megid. When he was seventeen, Rintaro received training from Ryo Ogami. He spent the majority of his early childhood with Kenshin Nagamine, who had trained him to inherit Lion Senki and Suiseiken Nagare. Very soon, Rintaro had lost his mother as well and became orphaned, later becoming adopted by the Sword of Logos. When Rintaro was still very young, his father left the family due to the nature of his job.

Rintaro Shindo was born the son of Shinjiro Shinozaki and an unnamed woman. Rintaro training with his master, Kenshin Nagamine.