Yuuki was separated from his mother at the age of five and grew up without knowing her love. The faint memory he has of his mother is that she was dignified, kind, and beautiful. For Yuuki, the few days he spent with his mother in his childhood were the only hope he had to live. Then, when Yuuki was 25, he received a letter from his mother saying she wanted to meet after 20 years. Without realizing that his feelings for his mother had turned into romantic love, Yuuki headed to the hot spring resort as promised.
