The name of the sender/writer of the card is "Moriyama(family name) Takeyoshi(given name)", who was a student of Yokosuka Naval Engineer Academy. Judging from what he wrote, it seems that the card was sent to his parents' home, but the family name of the recipient is different from the sender's. I don't know why.
contents of the card
greetings of late spring / early summer, grateful words to his(= the writer's) mother's letter. He is glad to hear the recipient of the card is going well, and says he keeps on studying, he has no shortage of daily commodities and money, so no need to send those to him. And at the end of the card, he says "Please take care of yourself and give my regards to everyone".
A sentence in the middle of the letter is what he really wanted to say. He recieved something* from the recipient of the post card without any trouble, but his local office has said nothing yet about that.
*(I can't decipher the second kanji of the word, but it might refer to 印鑑証明[inkan shōmei] "a certification of official registration of someone's name stamp", just in my impression.)