Vitya Kasatkin has an unusual hobby - he is engaged in Japanese sumo wrestling. His love for sumo was instilled in him by his father, who left the family 8 years ago and went to Japan. For many years, the boy has been living with one dream - to get to a youth tournament in Japan, in the hope that his father will see him, understand that he was wrong, and return to them.

Stepbrothers Zhenya and Tyoma do not like each other, despite playing on the same hockey team and living under the same roof. Professor Maksim Muromtsev, also Tyoma's father, is working on a time machine. Finding themselves in his laboratory, the guys are accidentally transported to 1999, where they meet 12-year-old Vadim Shipachyov - a future star hockey player and Zhenya's main idol. Now the guys must have time to help Vadim believe in himself and follow his dream before they can return to the present to lead their team to victory.

Father Frost decides to send Yaga to be re-educated by Petya, a boy who has his own problems - he wants to reconcile his parents before the New Year. Petya's parents spend more time working than they do with their family, and Petya wants to fix this situation before the New Year.

The contents of the Wonderful Doctor’s yellow suitcase cure not only colds and the flu, but also sadness, loneliness, cowardice, and timidity. Petya is a modern, reclusive boy who refuses to go outside; he is afraid of society and other children. His parents decide to turn to the Wonderful Doctor, but his magic suitcase is stolen. From that moment on, a series of adventures begins.