Found in Japanese tunic.

 

Going to need a much bigger photo than that.

Do these help?

Inside

Also has this sheet of paper folded inside.

Any help greatly appreciated. Thanks!

The front of the book simply says Takachiho Shoboukan (高千穗書房刊) = Takachiho (family name) Bookstore

 

The book is named inside the cover to Nakagami (family name) Minoru (given name) 中神実

 

The paper insert is a chart for visual and hand flag communications (including Morse Code) 視号手旗通信圖解 shigou tebata tsuushin zukai.

 

What I find most interesting is what is written in pencil and highlighted in red below. 海軍航空隊 Kaigun Koukuutai = Naval Aviation Corps

 

 

 

 

 

 

Wow! Thank you Eric!