you (honorific, to unmarried women)
Extremely formal, literary honorific second-person pronoun. Used in writing or period speech to address an unmarried woman respectfully. Not used in everyday modern Japanese.
"Where are you off to, young lady?" the old gentleman asked.
Compound of 貴 (ki, 'noble, esteemed') and 嬢 (jō, 'young lady, unmarried woman'). The exact historical derivation is uncertain; it appears in literary and formal registers as a respectful second-person pronoun for unmarried women.