Keio 3, Hinomoto, Eito. As the Bakumatsu throws Japan into turmoil, young Kuu Bashin dreams of becoming stronger through Standard Battle Spirits. His world changes when he encounters Ajara Zetsu, a wandering samurai and formidable Eternal Battler pursued by anti-shogunate forces. As the worlds of Standard and Eternal Battle collide, Kuu is pulled into Zetsu’s journey—and sets history in motion.

(Source: Crunchyroll)