Shingeki! Kyojin Chuugakkou

Eren and Mikasa enter a new school—Titan Junior High! However, Eren's hated Titans for years—can he get along with his new (harmless?) classmates? Featuring all of the characters from the main series as you've never seen them before, this series is sure to delight fans of Attack on Titan with a human vs. Titan volleyball match, a Titan rock band, and much more!
(Source: Kodansha USA)
Note: Chapter count includes 80 regular and 16 extra chapters.