This question came up in a Facebook group for translators that I am following. It’s a good question. Japanese names can be notoriously difficult to pin down. The same kanji characters often have multiple possible readings when used in names, including some creative ones that you wont’t find in a dictionary.
But is it really necessary to translate the Examiner’s name? If you have been asked to translate an office action from Japanese into English, chances are that the purpose of this translation is to inform an overseas applicant or their patent attorney. In other words, an overseas company has applied for a patent in Japan, the examiner has issued an office action, naturally in Japanese, and now that company or their representative, who cannot read Japanese, want to now what the examiner says.
The name of the examiner is pretty much irrelevant in this situation, and I cannot imagine a situation in which it will be of interest to the reader. So what can we do?
A simple solution is to put in a generic substitute like this:
Patent Office Examiner: [Name of the Examiner]
An alternative solution might to include a foot note like this:
Patent Office Examiner: Masanori KUBO*
* This rendering is the translator’s best guess. The correct transliteration might differ.
If, for some reason, you need to get it right, it might be possible to track down the name by trying to look them up on social media or even calling them (the Examiner’s phone number is usually listed at the bottom of the office action), but this is not a productive use of a translator’s time.

Of course, the same also applies to other personal names that you sometimes find on patent-related documents, such as inventors’ names on the front page of patent applications.