Dash!! Kappei (1981)

Kappei is a dramatically short guy but he is a master in every sport. He lives as a guest in sweet Akane's house, and he's in love with her, but there's a strange rival, her dog Salomone (Italian name) who plans evil traps to encumber Kappei. But the dog has also another function: he explains all sport rules when a new sport is depicted.