Shintoism and buddhism coexist as japan's two major religions because "Shinto is a more flexible religion, so it doesn't conflict with Buddhism."
The two religions, Shinto and Buddhism, coexist in harmony and even complement each other to a certain degree. Several Japanese citizens consider themselves Shintoist, Buddhist, or both.
Shintoism refers to the belief of kami (gods) representing objects in nature (flowers, trees, rocks, rivers); whereas Buddhism is concerned with the soul and the afterlife.