According to the research of Engyo MITAMURA, Hananoi was the same person as Karahashi (housemaid in O-oku), a senior lady-in-waiting of the Mito Domain, who had relations with Nariaki and got pregnant, and after she returned to Kyoto, she changed her name to Hananoi and went down to Nariaki's place again.
三田村鳶魚の取材によると、斉昭と通じて子を孕んだと言われる水戸藩老女唐橋(大奥女中)と同一人物で、京都に帰洛した後に花野井と改称して再び斉昭の元に赴いたとされる。