Updated: May 12, 2023
Contact Kenko for Kenko binoculars and accessories, Tokina lenses, Cosina cameras, and Slik tripods. They provide the following customer service phone number:
0120-162-414 (or 03-6840-0244)
Web site: http://www.kenko-tokina.co.jp/address.html
Addresses in Japanese to send a product for repair:
〒169-0073 東京都新宿区百人町1-9-20
ケンコー・トキナー 修理受付窓口
Phone 03-6840-3389
Also fill in this Japanese form and send it together with the product:
https://www.kenko-tokina.co.jp/support_adress.pdf
Note that Kenko-Tokina has terminated servicing all Konica, Minolta, and Konica-Minolta products.