True Mothers

Kiyokazu and Satoko Kurihara, a couple who had given up on having children, learned about a system called "special adoption" and welcomed a baby boy into their family. Six years had passed since then and the couple spent their days happily watching their son, Asato, grow up. One day, out of the blue, a woman named Hikari Katakura called them claiming to be Asato’s birth mother. "I want my child back, and if I can’t have him, then I want compensation." They had met Hikari only once. She was only 14 years old at the time, but she was a kind-hearted girl who entrusted Satoko with a letter to her unborn child. In the midst of swirling doubts, a young woman shows up at their door but this woman had no resemblance to the young girl they had met 6 years ago. Who is this woman and what is she after?