Lil' Leo by Moto Hagio

Two-year-old Leo is not your average house cat. One day he notices his young neighbor Tatsuru on his way to elementary school and he then decides to follow him and enroll himself! After receiving his own backpack and school supplies, young Leo realizes that anything Tatsuru can do, he can do as well! Leo can go to school! Leo can find a part-time job, become a mangaka or even be actor! Eventually Leo's life is full of wonderful memories, but it could have taken a very different turn if not for those who love him.