Nippon oil is a kind of oil made in Japan. Just like how you have different types of oils at home, like olive oil or vegetable oil, people in Japan use Nippon oil to make things like cars run smoothly. It's kind of like putting oil on your bike chain to make sure it doesn't get rusty and moves easily.
Nippon oil is special because it's made from crude oil that comes from deep underground. Some places in Japan have a lot of this crude oil, so they can use it to make Nippon oil. Scientists and engineers work really hard to turn the crude oil into Nippon oil, and they make sure it's safe and good for the environment.
So, basically, Nippon oil is a special type of oil made in Japan that helps things like cars run smoothly, and it's made from a special type of crude oil that comes from deep underground.