KINGDOM HEARTS BIRTH BY SLEEP LIGHT NOVEL SC

Ten years before Sora fought to save the worlds, three young Keyblade wielders named Terra, Aqua, and Ventus trained in the hopes of becoming Masters one day. But on the day of Terra and Aqua's Mark of Mastery exam, everything changed forever, and the three each set off on their own journey...

(W) Tomoco Kanemaki, Tetsuya Nomura (A) Shiro Amano