Four generations on the job!


One of the characteristics of Mitsubishi Materials plants is that they remain rooted in their communities, often for a very long time. Naoshima Smelter & Refinery, founded in 1917, is located on an island in the Seto Inland Sea north of Kagawa Prefecture with a population of about 3,000. Naoshima Smelter & Refinery, along with its related companies, employs some 1,000 of these people. Of these, some families have been working here for four generations, from current employee to great-grandfather. Mitsubishi Materials has been beloved for 150 years—and in that 150 years, there are employee families that have shared that love for four generations.

The people of Naoshima share strong bonds. Employees will have friends or relatives in every department, and, even if they don’t know someone, if they listen carefully, they might find that the stranger may in fact be someone acquainted with their father or grandfather. Older members and younger members communicate in a friendly, familiar way, as they have known each other since the younger members were children. In this kind of peaceful atmosphere, even people from outside the island also feel like part of the family as they do their work.

It’s a friendly workplace. New employees also feel free to keep in touch with others and collaborate as everyone shares and teaches each other about the difficult task of operating a copper smelter, and that makes for a strong plant. The father’s department handles a process; the child’s department handles the following process—it’s natural that parents and children in this situation will sometimes talk together about what’s happening in the workplace. Those connections are what make this a gold-medal-class operation.

―Let's actually inteview employees that have been working for four generations. Please introduce yourselves.

Koji Shimotsu (also referred to as “Koji” throughout the text): Hello. My name is Koji Shimotsu and I work in the Precious Metals Plant Section. I am involved in the casting and electrolysis of silver anodes (*1).

Tsubasa Shimotsu (also referred to as “Tsubasa” throughout the text): Greetings. My name is Tsubasa Shimotsu and I am from the Engineering Maintenance & Utility Section. My work includes electrical system maintenance and installation of new equipment. Koji happens to be my cousin.

Toshiki Morigami (also referred to as “Toshiki” throughout the text): Hello. My name is Toshiki Morigami and I work in the Precious Metals Plant Section. I am involved in the manufacture of gold beads which are used to make gold bullion.

Kenshiro Morigami (also referred to as “Kenshiro” throughout the text): Hello. My name is Kenshiro Morigami and I work in the Copper Smelter Section. I am working in a section that is involved in smelting copper ore at a high temperature and then refining it. I also happen to be Toshiki’s younger brother.

Taisei Shingu (also referred to as “Taisei” throughout the text): Hello. My name is Taisei Shingu and I work in the Acid Plant Section. Our section produces sulfuric acid using gas generated at the Copper Smelter Section.

―You all have family members that have been working at Naoshima Smelter & Refinery since your great-grandfather’s generation. What kind of work were (are) they involved with?

Koji: My father works in the Waste Water & Dust Treatment Section where he is involved in the treatment of waste water produced by the smelter. Although he is 69 years old, he is working under the reemployment system and trains his younger colleagues. My grandfather was a craftsman who inspected the equipment used in the smelter and also worked on finishing process of parts. He also managed the operation of the power plant here. My great-grandfather’s work tasks included copper deburring using a hammer (*2) and unloading ore using a shoulder carrying pole.

Tsubasa: My father used to work in the Copper Smelter Section. Immediately after graduating from junior high school, he entered a training school for craftsmen established by the former Mitsubishi Metals and started working here. He is a craftsman who has supported copper smelting and refining since before the Mitsubishi Continuous Smelting and Converting Process (*3) was invented. He is currently passing on the baton, the handling of analysis equipment, to his successor. My grandfather and great-grandfather worked just as Koji described.

Toshiki: The father of both Kenshiro and me works as a group leader(*4) in the Acid Plant Section. My paternal grandfather worked in the Copper Smelter Section and then in the Tank House Section. My paternal great-grandfather worked in the Tin Smelter Section, which existed at that time, where he was involved in tin manufacture.

Kenshiro: My father and uncle work in the Acid Plant Section and my maternal grandfather also worked in the same section. My maternal great-grandfather was involved in the task of drawing water from Okayama Prefecture to the island via underwater water pipes.

Taisei: My father works in the Copper Smelter Section. My maternal grandfather also worked in the Copper Smelter Section and my paternal grandfather worked at the power plant. My maternal great-grandfather worked in the General Affairs Section, and my paternal great-grandfather worked in the Acid Plant Section.

Company housing facilities (1947)

―How did you feel about possibly working someday at Mitsubishi Materials when you were a student?

Tsubasa: When I was in elementary school, I would say that 60% to 70% of my classmates came from families with members related to Mitsubishi Materials. Because of that influence, I dreamed of working for Mitsubishi Materials from the time I was in elementary school.

Kenshiro: When I was choosing my future career path, I was conscious of the fact that my family has worked at Mitsubishi Materials since my great-grandfather’s generation. I think the people of Naoshima have a sense that nothing can go wrong with working for Mitsubishi Materials.

Toshiki: My parents also told me that Mitsubishi Materials was a good, stable workplace. Among my 15 male classmates from junior high school, seven of them were hired by Mitsubishi Materials. Some of them went on to work at related companies while others that left the island at one point came back to work for us.

Koji: When I was a child, I heard my parents talking about their jobs when they came home from work, and it made me want to do what they did. Besides, the fact that I could work without leaving my hometown was also attractive.

―How does it feel to work in a company where you have many relatives and acquaintances working as well?

Toshiki: Naoshima is a place where people have strong ties with each other. I have friends and relatives in different sections. I have even known a senior colleague, who is six years older than me, since childhood, so we can interact with each other in a friendly atmosphere. Sometimes I do not know an employee but my father or grandfather does.

Kenshiro: When I joined the company, I was not worried about whether or not I would fit in well. We can easily communicate and cooperate with each other on the job, and we can teach each other about the difficult work of operating a copper smelter, which leads to the strength of the workplace. My father's section handles the process after my section, so he sometimes he asks me about the status of my own section.

Taisei: There is a large bath inside the changing room at the Naoshima Smelter & Refinery because one can get dirty working where the operations are being performed. I sometimes talk with my friends while taking a bath there.

Black copper casting (1947)

―Outside of work, is there any connection between Mitsubishi Materials and the local community?

Toshiki: There was a big forest fire in Naoshima that came very close to my house. Although I was shocked to see the forest burned down, I later had the opportunity to participate in a tree-planting activity organized by Mitsubishi Materials. I remember how happy I was to be able to help the local community by restoring the old greenery after the forest fire. Now the forest is lush and green, and I remember that experience whenever I pass by it.

Tsubasa: I'm a member of the Naoshima Smelter & Refinery soccer club. We sometimes form teams with not only employees but also local residents to play matches in Takamatsu and other places. I also teach soccer to children twice a month at the futsal court (*5) in Washinomatsu Sports Park, which was created by Mitsubishi Materials. Some of us also teach tennis.

Kenshiro: Most of our employees pass by Washinomatsu Sports Park on their way to or from work, so it's relaxing to see children that we know playing sports there on our way home. I sometimes play tennis with acquaintances from outside the company at the park and they are surprised that they can use such a great tennis court for free.

Koji: When I was in high school, I played in a game with the Mitsubishi Materials volleyball club. Later I joined that club directly after entering the company. I also experienced various other company club activities such as soccer, baseball, and badminton. Although I haven't been able to do this recently due to the COVID-19 pandemic, I am normally able to go straight to the company’s club (relaxation facility) (*5) for a drink right after playing sports.

  • *1Intermediate product prior to the production of pure silver. Pure copper is produced by anode electrolysis.
  • *2Removal of protrusions, etc. from cast copper.
  • *3A copper manufacturing technology developed by Mitsubishi Materials.
  • *4 A position like a team leader who organizes the operation site.
  • *5Both locations are employee welfare facilities owned by Naoshima Smelter & Refinery.