I'd also be interested in buying some (in Switzerland). Or do you have link for buying directly from Japan?

How can i buy it (i live in poland)

MKM 100GB Archival-grade BD-R
 

SKU: AABF25RTJP

Made in Japan by Mitsubishi Kagaku Media (old stock?)
Cost: ~US$500 for a 25-pack spindle

Label:

https://i.imgur.com/KtqNWXT.jpeg


MID:
https://i.imgur.com/uuVpPvu.png

Due to the VAMKM/IMk MID the disc can only be written with specific drives such as the Pioneer BDX-PR1MA. Verbatim advertises a 200-year-plus life and JIS Z 6017 compliance.