Long time ago....
Can you read it? I know u cant...here the translation..
Dear Masanori and Kiyoko,
Even though you can't see me, I'll always be watching you. When you grow up, follow the path you like and become a fine Japanese man and woman. Do not envy the fathers of others. Your father will become a god and watch you two closely. Both of you, study hard and help out your mother with work. I can't be your horse to ride, but you two be good friends. I am a cheerful person who flew a large bomber and finished off all the enemy. Please be an unbeatable person like your father and avenge my death.