Two photos from a vintage publication featuring a number of Type 97 Command Reconnaissance Aircraft or Mitsubishi Ki-15-I "Babs" belonging to the Kumagaya Army School as indicated by the tail marking. The school was based in Kumagaya, Saitama prefecture. When you visit the Wiki page note that the tail marking of the school is based on the city marking, itself based on the kanji of the city name, which is red.
Normally aircraft belonging to schools would be painted overall trainer orange but in this case the Ki-15 is a front-line reconnaissance aircraft and therefore left the Mitsubishi factory finished in gray (hairyokushoku). Kumagaya, which was mostly equipped with Tachikawa Ki-9 "Spruce" and Ki-55 "Ida", probably had this very small number of "Babs" to familiarise the pilots with more high performance aircraft. It would have been particularly tedious and time consuming to remove the overall paint and repaint every single Ki-15 while they were serving in the school only to have the colour change again if they were assigned to more needed front line units. Therefore it is safe to assume that the Ki-15s in the photos are finished in overall gray. Note the white lines on the cowling. In the IJNAF Zero these were applied for gun synchronisation. In IJNAF and IJAAF bombers sometimes they were applied in various fashion and position to help with bomb aiming. The Ki-15 had neither forward firing guns nor any bombs so these were probably applied to help pilots stay in formation during in-flight formation training.
Of interest is the twin engine aircraft in the foreground on the left in the bottom photo.
Small quiz: what type do you think it is?