I am sorry to hear about that. I didn't know him at all but from your words I can see that Mr. Yamamoto Kiyokazu was an incredible individual. My condolences to you as well as his family.
I'd like to invite you to participate in my Art Curation Initiative #5
Thank you very much @trincowski... yeah, another period has come...
There's no one like him educate people with big affection :(