[2] Modern Japanese historians reject the theory of a female head of the Ii clan, such as Kazuto Hongō, history professor of University of Tokyo.
[13] Atsuyuki Wakabayashi from Shizuoka University has stated that the letter was co-signed between Jirō Hōshi and Sekiguchi Naotora as an imperial edict.
[16] This statement was based on several facts: Another Japanese historian, Motoki Kuroda from Komazawa University, also supported the theory that Ii Naotora was a son of Sekiguchi Ujitsune.
[6] Similarly, Daimon Watanabe, a history professor from Bukkyo University, also rejected the supplementary sources of Moriyasu Kō shoki about the female Naotora theory,[j] as he says the scripts were copied from an unverified Edo period book.
[11] He supported the theory that Ii Naotora and Jiro-Hoshi were the same people but male, based on the evident confusions of previous historians about the identity.
Otazu no Kata who was wife of Iio Tsurutatsu (lord of Hikuma castle) invited Naohira to a meeting with her husband and planned to eradicate it to claim prominence in Totomi.
Following Naohira's death, Jiro Hoshi returned to secular life the male name Naotora and declared herself the nominal head of the Ii clan.
[10] During the early days of Naotora's reign in 1564, Niino Chikanori, a retainer of Ii clan, sieged the Hikuma castle to prove Naotora's loyalty to Imagawa Ujizane; Otazu and Tsurutatsu fought to defend the castle and Chikanori was killed.