Lucia

Lucia was isolated for her entire existence as her only purpose was to heal the Blue Star without any interaction with the people of Lunar. As such, she knew nothing of the human world and is very naive and curious about the aspects of Lunar. Lucia knew nothing of human emotion either, so initially, she is very serious to the point of being insensitive. As a running gag, she could also take things people said to literally. When Lucia meets Hiro and Ruby, she begins to experience the depths of human emotion a little at a time. By the time she meets the whole group, she has integrated herself into Lunar and become good friends with everyone. She learns to feel compassion, sadness, worry, anger, relief, gratefulness, embarrassment, and most importantly, love. Lucia essentially gains her humanity through her relationships with her friends. Source: http://lunar.wikia.com/wiki/Lucia