Pray for good luck in battle - written horizontally (right to left) on the top
Destroy England and America - written under the red disc.
Certain victory for the empire - written under the red disc.
Soldier's Support Oranization, Tokyo Chapter. Nishiyama ?
Looks highly suspicious. The phrases sound suspicious, the writing looks suspicious, the emptiness of the flag makes it feel sad rather than something a school or factory or neighborhood would present to a departing soldier. The addressee is completely illegible to me, which I find strange as usually one would expect the writer to take great care in writing the addressee's name. But this could be a question of skill in deciphering handwritten letters on my part.