The Kazama family has been a single-parent household, supporting each other until now. However, after their only son Koji came of age, he started working away from home to send money home to make life easier for his mother. After a year of living apart like this, Koji finally gets a long weekend and decides to go back to his parents' house to find his mother there, but... His mother, overwhelmed with loneliness, climaxes over and over again with her beloved son's cock, not knowing when she'll see him again.