Japan - Koseki Tohon

[smokeface 17]

Hey guys, I am an American with a Filipina fiancee. She was previously married to a Japanese man and they divorced in Japan. We have reason to believe he may be deceased (old age). We already know she needs to get his Koseki Tohon for the visa process. She will be living in the Philippines, and her divorce is not recognized there. My question is if he did pass away in Japan and it was reported would it be on his Koseki Tohon? Does it matter if he passed somewhere in Japan other than where the Koseki Tohon is registered? If it's possible it would not show up, how could we go about finding out if he is deceased? She already checked in the Philippines but they found no records, so I'm wondering if she checks in Japan how does she go about doing this? She has not spoken to him in close to 10 years so she has no idea where he is or has been living. If we find out he has passed it will make things easier because she can be free to marry in the Philippines as well as Japan/US. If we don't find out it will be fine because she can use the divorce decree from Japan and Koseki Tohon to get the visa. Thank you.