Chelsea is a noble. Her brother Gilbert is the commander of the divisions that Calintz and the other division officers are in charge of. Chelsea is not a noble by birth. Gilbert adopted her as a sister and as a result, she became a noble in name.
Chelsea had been in a different division. However, after fighting against monsters alongside with Calintz, she approves of Calintz's method of operation and decides to join the 7th division. She is often found quarreling with Roffma over the matter superiority and inferiority of class rankings, intelligence, and lifestyle of themselves. She often criticizes Roffma for his stupidity, his bulkiness and the quality lacking in those of a gentleman.
Chelsea is a playable character right after she joins the 7th division. Her weapon is a wand, and her fighting style involves magic.