noun
missy; young lady
Casual, slightly dated term for a young girl or young woman, often used in a familiar or affectionate way. Not a formal title.
あのミッシーはいつも元気だね。
That young lady is always so energetic, isn't she?
ミッシー、ちょっとこっちに来てごらん。
Missy, come here for a moment.