Whose Is the Cuckoo's Egg?

Hida Kazami aspires to be a top skier just like her father Hiromasa. One day, it is discovered that she has a gene that only top athletes have. Wanting to unlock this mystery, a gene researcher Yuzuki Yosuke approaches Hiromasa to carry out research. But Hiromasa stubbornly refuses because he is burdened with the horrible past associated with his daughter's birth. 10 years ago, a newborn was kidnapped and his wife died. Who are the parents of this daughter? Distressing facts are revealed one after another, and then an inexplicable event.