If you have lost your return envelope, you can purchase a "Letter Pack Light 430" at a post office for 430 JPY.
It can also be purchased at convenience stores such as Lawson and Seven-Eleven, etc.
Please use "Letter Pack Light 430" and send the package to the following address
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3-4-19 Aomi, Koto-ku, Tokyo
Aomi Center Bldg. 1, 3F1-4
135-0064
SB Framework (COOCOM)
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After posting your package, please inform us of the tracking number on the new envelope by clicking "Submit a request".
*The tracking number can be found in the position circled in red in the image below.
Please let us know if this does not help.