Nanase's family is a wealthy one. Nanase Miyou was about to give birth, but her husband wasn't around due to his work commitments. Only her mother,Nanase Ayano, stayed with her until she finally made it. It was a twin boy. Ayano is the one who gives them a name, which is Nanase Tenn for the older one and Nanase Riku for the younger one. Miyou was grateful that she gave birth to a perfect twin, as they brought so much joy and love into her life. She couldn't have asked for anything more. Her husband,Nanase Nishi, hasn't picked up the call yet. Miyou wondered where he could be. After a few days,Miyou still stayed at the hospital until she was stable. Ayano feels like something is wrong with the younger one, so she asks the doctor to do some tests on the twin. After the test is done,the doctor finds out that the younger person has suffered from a rare illness that can be classified as a chronic illness. They can't do anything yet because he is still a baby, but they will closely monitor his condition and seek appropriate treatment as he grows older. Miyou still remember that Nishi once said that if he got a sick son,he would kill it immediately because he believes it's better than watching them suffer. Miyou can't accept that, and she also can't hide it too, because what if Riku showed some signs and Nishi found out? Of course, he would throw Riku away. Her husband doesn't know about the twin yet because he hasn't picked up the call. Then Ayano,Miyou's mother, decides to take care of Riku so Miyou can visit him for anything she likes without Nishi finding out. Miyou hesitated at first, but it was good for Riku's sake. Then Miyou gave Riku to Ayano, even though she felt guilty about it.