Nidoto Touranai Tabibito

A traveler seeking protection from a storm knocks on the door of a house. The family turns him away as they have a sick daughter and don't want the trouble. The traveler pities the daughter and gives them medicine. A doctor comes to visit next and says that's the medicine the daughter needs. The takes it and gets better. The family is ashamed of their inhospitality and promise to let the traveler stay if they come by again. The traveler ever did.