Vertically down the right side
祈武運長久
Inoru bū-un chōkyū (means: Pray for (your) good luck in battle)
柴田荘次
Shibata Shōji (presumably the recipient's name)
Most everything else is a name.
I have my doubts about authenticity. Well, I'm suspicious of almost all of these things, unless they stand out as unusually specific to a person or a place or a time. This just has names and the most vanilla of good luck slogans on it. Well, slightly to the left of Shibata Shōji's name, there is the phrase "congratulations on your enlistment". Other than that, its pretty generic.
Not an obvious fake, but not fabulously convincing either.