Categorize the following countries according to continent: Spain, Mexico, China, Japan.
Spain, Mexico, China, Japan
Europe: Spain
Americas: Mexico
Asia: China, Japan
Below is an instruction that describes a task. Write a response that appropriately completes the request.

### Instruction:
Categorize the following countries according to continent: Spain, Mexico, China, Japan.

### Response:
Europe: Spain
Americas: Mexico
Asia: China, Japan