Mister Ses finds he is living in an abode on Stockville Elementary Academy's east schoolyard side before he's discreetly discovered by a boy named Lesley. Awestricken by him, Lesley decides to place him in his suit pocket to sneak him into class. Months go by and no one ever notices Mister Ses as they soak up their teacher's lessons. Mister Ses's wittiness and wisdom is mesmerizing! Their teacher assigns Mister Ses a typical student desk. He learns the French alphabet, and helps Lesley to understand difficult lessons. At the end of the school year, every student earns a promotion. Though Mister Ses is self-conscious of his large size, nevertheless, he knows he will try his best!