write a (without chapters) detailed fan fiction for 4000 words from anime "Golden Kamuy" how Second Lieutenant NAME_1 NAME_2 walked past First NAME_3's office and heard strange noises like moanings. He pressed his ear and heard dirty talk and more moaning. He saw in shock how Officer Iwasaki NAME_4, the only one female soldier from 7th division, and First NAME_3 were doing "it".