- Lucille Callahan or (Lucy): Lucy is a reclusive math genius who was struck by lightning when she was 8 and is afraid of germs.
- Levi: Levi is a kindhearted boy who loves taking pictures and uploading them on his website and also loves dogs.
- Windy Sitton: Windy loves a charity case and also likes musicals and is slightly bossy but a wonderful friend.
- Grandma: Grandma is Lucy’s grandmother and always wants to help Lucy if she is going through a bad time but she is stubborn and once she decides something she does never backs down.
- Cutie Pi: Cutie Pi is a kind light brown beagle dog who fell in love with Lucy but has rare brain cancer and is terminally ill.