Typically Japanese women were not raped by Japanese troops. In the event that something like that did occur, there was a section of the Japanese penal code that specifically addressed this:

From Section 9 of the 1908 Japanese Army Penal Code:

第八十六条　戦地又ハ帝国軍ノ占領地ニ於テ住民ノ財物ヲ掠奪シタル者ハ一年以上ノ有期懲役ニ処ス 2　前項ノ罪ヲ犯スニ当リ婦女ヲ強姦シタルトキハ無期又ハ七年以上ノ懲役ニ処ス

which is roughly translated to:

Article 86: Looting of private property in zones under Japanese Imperial military occupation will be punished by a minimum of 1-year in prison (up to a fixed limit). Rape of women in an area under Japanese Imperial military occupation will be punished for a minimum of 7 years up to life imprisonment.

Unfortunately, this legal code was not enforceable in Japan's war zones due to Japan's piss poor logistical structure and a large amount of leeway by on-the-ground field officers, who often looked the other way or were themselves complicit in war crimes.