When a Mexican Death Bear Monster runs amok at school, Randy and Howard realize they should have paid more attention during Spanish class.

Randy's Ninja responsibilities drive a wedge between him and Howard during their rehearsals for Norrisville's Battle of the Bands, leaving Randy to figure out a way to balance his Ninja duties with being Howard's friend.

When a real monster disrupts Norrisville High's annual practice Monster Drill, Randy must retrieve his Ninja mask and the NinjaNomicon in order to save entire school.