Samurai 8: The Tale of Hachimaru, Vol. 3: Kotsuga & Ryu — Masashi Kishimoto

Hachimaru has survived the attack of the deadly assassin Ata, but he's not out of danger just yet. When the moon starts plummeting toward the planet, Hachimaru will have to use his master's powerful technique to save everyone! But in order to save the entire galaxy, the other samurai keys will have to be found. What kinds of trouble await Hachimaru as he leaves his home for the first time?