If you teach Modern Japan you are probably used to having lots of cool pictures to show your students. You probably pinch a lot of them from the MIT Visualizing Cultures site. A new book that you should be aware of is.
Hu, Philip, Rhiannon Paget, Sebastian Dobson, Maki Kaneko, and Andreas Marks. Conflicts of Interest: Art and War in Modern Japan. Saint Louis: University of Washington Press, 2016.
This is based on the impressive collection of Japanese war-related prints, board games, clothing etc at the St. Louis Museum of Art. There was apparently an exhibition, but I missed it at the time. They have nice pictures of images you have probably seen before, but also lots of stuff I have not seen before.
Rowdy Satsuma women disturbing the peace in 1877. (All of these have great descriptions to explain the context.)
The Battle of the Yalu, looking a bit less glorious than it does in many prints
The girl he left behind (from the cover of a novel)
There are also some good essays on how war fits into modern Japanese visual culture.
There is a lot more in there. This book makes a great gift for the Japan person in your life. I assume you can get it from the museum shop, but is is also available on a well-known South American website.