"I'm sorry. I've been feeling unwell all of a sudden..." Mimi said this to her husband and son on a Saturday as they were about to go to an amusement park. Worried about Mimi, her husband and son went off to the park, but... A few minutes later, Saburo, a young man she met at her part-time job and who she has sex with, came to her house. Usually, the two of them would meet up out of sight of her family, but today they had decided to have "unlimited fuck within a certain time" at Mimi's house until her family returned home...