Answer:
The American architect who often used reinforced concrete and cantilevers in his buildings, and was greatly influenced by the Japanese respect for nature and materials, is Frank Lloyd Wright.
Wright is known for his organic architecture philosophy, which emphasized the harmony between human habitation and the natural world. He believed that buildings should be designed in harmony with their surroundings, and that architecture should be functional as well as aesthetic.
He frequently used reinforced concrete and cantilevers in his designs, which allowed for large spans and dramatic overhangs. Some of his most famous buildings include Fallingwater, the Guggenheim Museum in New York City, and the Unity Temple in Illinois.
Wright was also influenced by Japanese architecture, particularly the traditional Japanese concept of "Ma," which emphasizes the importance of negative space and the gaps between objects. This is evident in many of his designs, which feature open floor plans and large windows that blur the line between indoor and outdoor spaces.