Requesting opinion and translation of Yosegaki Hinomaru

At the end of WWII, my father-in-law brought this flag back from the Philippines where he served with the U.S. Army as a medical assistant. I am thinking about sending it to the Obon Society for possible return to the owner's family, but first, I would be grateful for your opinion regarding its authenticity. Secondarily, I would like a translation of the phrases written in large characters. From reading previous threads, I believe that the phrase along the bottom of the flag is the common one regarding Prayers For Everlasting Fortune In Battle, but I cannot find any references to the one that is written vertically at the bottom right. I have also included pictures of some sections of smaller characters to aid in your evaluation and on the chance that they might include the owner's name or his home town. Thank you for your assistance.

Looks like Nishiura Sadao (西浦定夫) which would presumably be the name of the person to whom the flag was presented. The rest are just names. Looks a little bit strange because of the vertical orientation. Can't say for sure if its real or not.

There are two more slogans there.
1) upper side
玉砕報(most likely 国)
Gyokusai Hōkoku
honorable death for the country

2) middle left
忠？(The second kanji is illegible. It could be 義.)

Majestic and Toritoribe,
Thank you for your help.

Good news! The OBON Society has found the son of Nishiura Sadao in Osaka Prefecture and will be returning the flag to him. I was also pleased to learn that Nishiura Sadao survived the war.

That's great news. When did you contact them? I'm just curious how long it took them to resolve the case.

Wow...Thank you for coming back to us and letting us know. Great news.

I sent the flag to the OBON Society in mid-2016. They got back to me within a few months to confirm the soldier's name -- something that Majestic had already given me. It was not until a month or two ago that they told me about finding his son. I do not know anything about their investigative process or the difficulty posed by this particular case. However, I imagine that it cannot be easy because of the number of years that have passed since 1945. I believe that the society is relatively small and faces all the manpower and financial problems typical of organizations of that size. For these reasons, I try to send them a contribution every year.