Final answer:
The Japanese allowed Japanese Brazilians to re-enter Japan due to historical ties and a labor shortage in Japan.
Step-by-step explanation:
The Japanese allowed the Japanese Brazilians to re-enter Japan because of the historical ties between Japan and Brazil. In the early 20th century, the Japanese government entered into an agreement with Brazil to allow Japanese laborers to work on coffee plantations. Many Japanese immigrants in Brazil found themselves trapped in debt bondage and unable to return to Japan. In the 20th century, Japan experienced a labor shortage and the Japanese Brazilian community served as a valuable source of labor, leading to their re-entry into Japan.