Over the following months, O'Herne and six other Dutch women were repeatedly raped and beaten, day and night, by Japanese personnel. According to Japanese historian Yoshiaki Yoshimi , however, the comfort stations did not solve, but aggravated the first two problems. Yoshimi has asserted, "The Japanese Imperial Army feared most that the simmering discontentment of the soldiers could explode into a riot and revolt. That is why it provided women". Earlier comfort women were Japanese prostitutes who volunteered for such service.