Correction:
The second kanji mdchachi-san mentioned is 睦 of 睦子 Mutsuko, not 曠.
Additional information (names in bold font are written on the flag):
I found very interesting facts.
The recipient of the flag is
馬越轄五. He was the 6th son of 馬越幸次郎, and 幸次郎's father was 馬越恭平, a famous business person and a member of the House of Peers.
幸次郎's 1st son, i.e., the recipient's older brother was 馬越恭一. 恭一's wife was
武子, and her father was
井上三郎. (Incidentally, 三郎 was the husband of the 2nd daughter of 井上馨, and 馬越恭平 used to work at 井上馨's company.)
馬越幸次郎's 4th son, i.e., the recipient's another older brother was 慎思. 慎思's wife was
睦子, and her father was
鷹司信熙.
泰禄郎 was 幸次郎's 7th son, i.e., the recipient's younger brother.
順二 was 幸次郎's adopted child.
陸軍少尉 (Army Second Lieutenant)
馬越謹参 was 幸次郎's 3rd son, i.e., the recipient's another older brother.
In conclusion;
(馬越)
武子: the recipient's sister-in-law
(馬越)
睦子: his sister-in-law
泰禄郎: his brother
順二: his brother
馬越謹参: his brother
井上三郎: father of his sister-in-law
鷹司信熙: father of his sister-in-law
真男 and
牧子 would be also a member of 馬越 family, and
井上大佐 and
井上晧子 would be a relative of
井上三郎.
Well, it's reasonable that there are many famous names on the flag...
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