Bruiser, a mischievous Jack Russell Terrier, wakes up ready for an adventure. After devising a plan to sneak into Mr. David’s preschool, Bruiser weasels his way into different classrooms, meeting new friends and causing many mishaps–mishaps that get many of the students in trouble! After seeing the students sitting out during recess, a new friend helps Bruiser realize that he should take responsibility for his actions. Bruiser then decides to make matters better for all.