Rena gave birth to Tatsuaki as a single mother. The father told her to abort, but Rena insisted on keeping the baby. Since then, she has had no contact with him. Rena worked tirelessly as a career woman to ensure that her son wouldn't feel pitied for growing up in a single-parent household. Tatsuaki understood the situation and never made demands, but his loneliness grew over time. When Tatsuaki was about to enter university, Rena took accumulated paid leave to go on a trip with him. However, Rena was only thinking about work.
