Nao Midorikawa  is one of the main heroine in Smile Pretty Cure!. She is a plucky girl with a strong sense of justice, and has no tolerance for wrongdoers. An older sister-type, she is popular even with the girls. While tough, she also has a feminine side, as she loves cute things. Excellent at sports, she is part of the girls' soccer team.

Nao is said to have a strong sense of justice and does not easily forgive one's wrong actions. She is also known for her powerful courage, but despite her bravery, she has a big fear of insects and ghosts. At times she can become competitive when playing sports, and sometimes she may act forcefully around others, but she has a good heart and she is very popular for her kindness and talent. Nao values her family very highly, as evidenced in her interactions with her parents and siblings. Her worst fear would be to lose them. She often takes care of her siblings when her parents cannot and she enjoys playing with them.