#14 Tsubasa Yamanaka, the Master Plastics Polisher Behind Toyota's Stunning Finishes


The process of molding plastic car parts inevitably leaves behind some faint work lines. To achieve the stunning finish of a Century bumper, one master plastics polisher smooths these markings down to thousandths of a millimeter.

Nurturing the Century mindset

Born in October 1983, the 39-year-old Yamanaka describes himself as “a poor public speaker, the type who would rather quietly get on with work.” After graduating from a technical high school in his hometown of Kobe, Hyogo Prefecture, he worked at a factory producing cell phone LCDs before joining Toyota in 2007 at the age of 23. Ever since, Yamanaka has dedicated his career to what is now the Bumper Manufacturing Section of the Tahara Plant’s Paint & Plastics Molding Division.


The Paint & Plastics Molding Division is divided into different teams that handle injection molding, painting, and assembly, where ornamental features and other parts are added after painting. I’m part of the painting group and have mainly been responsible for polishing and repairing defects on painted surfaces.

Our models include the Land Cruiser and 4Runner (Hilux Surf in Japan).

At one point, I was involved in the process of spray painting plastic parts by hand, but with nearly all of that work now automated, I have been contributing to carmaking with my polishing skills for a long time.

Since becoming an Expert in 2018, Yamanaka has simultaneously been tasked with preparing painting processes for new model production.

In 2022, he also participated in a project to restore the first-generation Crown, part of Toyota’s training to foster highly skilled technicians with a firm grasp of fundamental monozukuri principles. Soon after completing the training and returning to his post at Tahara, Yamanaka was selected for the new Century project.


The Century is the car that truly represents Toyota, so I felt a great deal of pressure to be given the role, and that has stayed with me since.

At the same time, I was motivated by the thought that, with the Century, we could pursue the highest quality and an all-out dedication to monozukuri.

As Yamanaka explains, staff who work on the Century first undergo training to nurture the right mindset. They are briefed on everything from the Century’s history to a production approach and carmaking mentality that differs from other models.


For example, whereas TPS (Toyota Production System) aims to eliminate waste in the production process completely, I learned that a different approach is taken for the Century.

This certainly doesn’t mean that we ignore TPS. Instead, the idea is that any time saved by streamlining operations goes into improving quality.

Looking at my own PL polishing process, we have an image clarity criterion for assessing the appearance and quality of painted body surfaces. However, the Century has its own very strict standard, which is why the PL polishing process is necessary.

Yamanaka’s workspace features evenly spaced parallel lights that help him check the smoothness of bumper surfaces.