Ms. Mystery (ミステリーちゃん, Misuterī-chan) is a Ham-Ham who appears in some of the Japanese episodes. She is able to predict the future with her magical crystal ball; when she does so she says 'atarinchu'. Magical is her little brother and assistant. Mystery is never seen without her pink costume. She even wears it while sleeping, as shown in Lady Lapis!.
Mystery is very cheerful and optimistic, she never becomes angry with anyone or anything. She is very confident with her predictions and is always certain they'll come true. Though her predictions aren't always 100% correct, her little brother Magical will always be there to say otherwise.
In Lady Lapis!, Magical mentions waking her up would be bad, which could mean she can be cranky if woken too early.
See also: Ms. Mystery/Gallery