Melissa is a young woman with straight blonde hair long enough to stretch down her back. She has deep sky blue eyes and a pair of red, oval frame eyeglasses. Melissa normally wears a white dress shirt with orange plaid trim sleeves, underneath a red vest with an orange plaid bow tie at the collar. Accompanying this are knee length khaki pants, salmon plaid leggings, and boots. She also sports a watch on her left wrist.
Melissa is a kind and very intelligent girl who maintains a positive attitude despite being Quirkless. It also seems that she is very humble about her creations. In addition, she cares deeply for her father and wants to reunite him with his old friend All Might.
While schools in Japan are on vacation, Melissa Shield sends an email to U.A. Teacher and No.1 Hero: All Might. In her message, she asks All Might to come and visit her father on I-Island for an upcoming expo. She hopes that All Might will reunite with her father and she expresses that she can't wait to see his reaction.
- Melissa refers to All Might as "Uncle Might". It is most likely due to the closeness that he and her father share.
- According to Melissa, she had given up on being a hero a while ago. Instead, she wants to be like her father who saves people’s lives, but saves them indirectly.