Valentine marries at the end of the 19th century, and love passes through her family from generation to generation.

Set in the 1960’s, high school student Toru Watanabe loses his only friend Kizuki after he commits suicide. Toru, now looking for a new life, enters a university in Tokyo. By chance, Toru meets Kizuki’s ex-girlfriend Naoko in the university. They grow close because they both share the same loss. As Toru and Naoko grow even closer, Naoko’s sense of loss also grows. After Naoko’s 20th birthday, she leaves for a sanitarium in Kyoto. Watanabe, devastated by the situation, meets pure-hearted Midori during the spring semester. Midori looks like a small animal that just came into the world …

Kline, a former Los Angeles police officer turned private detective, is hired by a powerful pharmaceutical conglomerate boss to investigate in Asia the disappearance of his only son, Shitao, whom he has not seen in person since the boy was ten. Now in his 30s, Shitao has gone missing in the Philippines where he had been helping in an orphanage.