Her classmates at school called her Key, as in the "key" to a strange mystery. Key's "grandfather" was a kindly old scientist wanting to use his skill in robotics to create peace and love in the world. But when that kindly old scientist passed away, poor Key was left behind, lacking even the ability to smile. There still is hope, however—a message left behind for Key suggests a fantastic possibility. Could it really be possible for Key to become a real, live human, if she can only win the love of 30,000 people?

[Source: Crunchyroll]