Mitsubishi Ki-21 "Sally" - Rikugun Koku Seibi Gakko #2

Here's another photo, from the Arawasi collection this time, featuring a Nakajima built Model 1 "Sally" from the Army Maintenance School.

In the background is another "Sally" with the hiragana お (O) on the tail and a Kawasaki Ki-32 "Mary".