Japan is known for producing high-quality and technologically advanced CNC machines, and many of them are well-known and widely used in various industries worldwide. However, the best-selling Japanese CNC machines can vary depending on the specific application, industry, and region. Here are some popular and widely used Japanese CNC machine brands and models:

1. Mazak CNC machines – Mazak is a leading Japanese brand in the CNC machine industry, known for their high precision, efficiency, and versatility. They offer a wide range of models for different applications and industries, such as machining centers, turning centers, and laser machines.
2. Mori Seiki CNC machines – Mori Seiki is another well-known Japanese brand in the CNC machine industry, known for their high precision and reliability. They offer a wide range of models for different applications and industries, such as machining centers, turning centers, and grinding machines.
3. Okuma CNC machines – Okuma is a well-known Japanese brand in the CNC machine industry, known for their high precision and durability. They offer a wide range of models for different applications and industries, such as machining centers, turning centers, and grinding machines.
4. Yasda CNC machines – Yasda is a well-known Japanese brand in the CNC machine industry, known for their high precision and productivity. They offer a wide range of models for different applications and industries, such as machining centers and precision jig borers.
5. Fanuc CNC machines – Fanuc is a well-known Japanese brand in the CNC machine industry, known for their high precision, reliability and easy maintenance. They offer a wide range of models for different applications and industries, such as machining centers, turning centers, and robots.

It’s worth noting that the best-selling Japanese CNC machines also depend on the region, some brands might be more popular in one region than another. Also, the best-selling models change over time as new technologies and models are introduced, so the list above may not always be the most up-to-date.