Kikou and kiden are both pronouns primarily being spectres of epistolary and courtly discourse. Nevertheless, they once in a while resurface in pop-culture as a more decorous if archaic alternative the tried and tested anata.
Honourable Duke - "Kikou"
The pronoun is spelled with the kanji 貴公, literally "honourable duke", though the latter refers to a much more ancient title of administrative nobility of the Zhou dynasty, namely the Gong. It was considered the pinnacle of the hierarchy of Chinese nobility during the 1000s to the 700s BCE, it switched in significance over the dynasties, but nevertheless remained a high degree of status.
The title was used in Japan as a lordly honorific with a loose sense of the addressee having an actual position of power or have had it in the past thus earning them the respect.
Honourable Hall- "Kiden"