Tatsu and Yuki, though mother and son, ended up having a physical relationship. After finding a job, Yuki eventually left his mother's side, but Tatsu still saw him as her beloved partner. One day, Yuki suddenly contacted her saying, 'I have a girlfriend now,' which made Tatsu fiercely jealous. She then said, 'Come see me at the hot spring inn for old times' sake,' and summoned Yuki.
