The kindergarten program, Tools of the Mind (Tools), has been shown to improve executive functions (as assessed by laboratory measures) and academic performance. The objective here was to see if Tools can improve executive functions in the real world (in the classroom), academic outcomes not previously investigated, reduce bullying and peer ostracism, and increase teachers' and students' joy in being in the classroom. This first randomized controlled trial of Tools in Canada included 351 kindergarten children (mean age 5.2 years at entry; 51% female) in 18 public schools. Stratified randomization resulted in teachers and students in both groups being closely matched. Teachers in both groups received the same number of training hours and same funds for new materials. Outcome measures were pre and post standardized academic skill assessments and teacher online survey responses. This study replicated that Tools improves reading and shows for the first time that it improves writing (far exceeding levels the school districts had seen before), self-control and attention-regulation in the real world (e.g., time on task without supervision), reduces teacher burnout and children being ostracized or excluded, and increases the joy students and teachers experience in school. By Spring, Tools teachers were still enthusiastic about teaching; control teachers were exhausted. These results were not only better than the control group but also better than Tools teachers experienced the year before Tools. Thus, children in a kindergarten curriculum that emphasized play, improving self-regulation, working together and helping one another, and hands-on learning performed better academically, showed less bullying and peer ostracism and more kindness and helping behavior than students in more traditional classes, and teacher enthusiasm for teaching soared. Tools reduced initial disparities separating children, schools, and teachers.