Can anyone identify this Japanese signature/autograph? (... Yokoyama)

[Neighbor]

Thank you for all the information/effort.

I want to be as certain a I can (plus still question what appears to be the abbreviated first name "Is."/similar) - as it doesn't seem to make sense if first name is "Hiroshi".

I certainly apologize for not taking better pictures before posting the first time - but I've taken some with a flash/now uploaded - that help separate the colors in the ink and I hope will lead to a more obvious conclusion.

[ghp95134]

... perhaps the initial is a fancy "H" ? If I squint my eyes and resort to that single-malt scotch I mentioned earlier, I could see it as "H".

-- Guy