This is an animated TV show where there is a group of three friends that can summon monsters. They all have main monsters that they summon. The main character normally summons a dragon-like creature that can fly. His friend can summon a short blue four-armed water creature and his friend that is a girl can summon a mole-like creature I think.  At the end of the season, I think all the creatures get ultimate forms and I remember most distinctly that the blue creature became four miniature clones of itself. There was one episode where one of the monsters infested the school and they had to stop them. I think that the monsters come from different worlds like a light world, a dark world, a forest world, a fire world, a water world, but I don’t remember anymore than that.