The Imperial Japanese were a very dangerous adversary.
Late-war Japanese tanks and their maximum gun depression:
Type 1 medium tank Chi-he: -15 degrees.
Type 2 I gun tank Ho-I, 57 mm tan gun version: -15 degrees.
Type 4 medium tank Chi-to: -10 degrees.
Type 5 medium tank Chi-ri: -10 degrees.
Most late-war Japanese tanks had outstanding gun depression values, as they were designed primarily to defend the Japanese home islands from Allied invasion. The somewhat hilly terrain of Japan could then be utilized as an advantage. The same feature can also be found on post-war Japanese tank designs such as the Type 61 and Type 74.