On a clear and sunny day, Mickey (voiced by Walt Disney), wearing a top hat and carrying a cane, hums a cheerful tune as he arrives at Minnie's (voiced by Marcellite Garner) house. The room is already filled with countless little animals, all good friends of Mickey and Minnie, gathered there today to celebrate Mickey's birthday. Hearing the knock at the door, Minnie orders everyone to hide. After opening the door, Mickey and Minnie greet each other, when suddenly all the little animals jump out, shouting "Surprise!" The plump chef brings out a tempting birthday cake, and good friends have also prepared gifts for Mickey. Inside is a piano. Overjoyed, Mickey hops over to the piano and, together with Minnie, plays a lively tune. The good friends dance to the music, and a lively party unfolds right in the room. This is Mickey's birthday, and a celebration for all his good friends...