Probably not. Its more likely supply depots and troop stations were the locations of comfort women brothels. It would be unusual to find comfort women stationed at the front lines, due to the logistics involved. Moreover where heavy fighting was taken place, the Japanese army would have wanted its troops attentions on battle and not sex.
However, where the front lines were stable for lond durations its more than likely, comfort women were present such as in China. Some comfort women were liberated/rescued by advancing allied soldiers so it is likely that at some point, they would have been realtively close to the front lines in other theatres. Or quite possibly they were left behind, when the allies made sweeping territorial advanaces in the final years of the war.
With some Japanese units switching theatres fairly frequently, it would be more likely that the confort women would remain in a certain theatre for a long duration. For instance, comfort women in China would not have switched to Gaudacanal, when Japanese Divisions launched a campaign here. So they would not have been tied to specific Japanese units. Rather specific areas.
