There are several theories regarding the identity of the head of Ii clan after Ii Naomori. The "Ii clan history" record which now preserved in the Shizuoka central library was the oldest source supporting the theory that
Jirō Hōshi (次郎法師), was a female Ii Naotora were from secondary material which first appeared in mid
Edo period document which written by a priest at Ryutanji Temple (Hamamatsu City). However, this popular theory is disputed by 20th century academics. Historian
Suzuki Masanori speculates that he was the son of Ii Naomori. However, since the
Zatsuhisetsu Shaki records that Inojiro was the son of Sekiguchi
Echigo-no-Kami (Ujitsune), several researchers have suggested that Naotora was the son of Sekiguchi Ujitsune, he is thought to have married the daughter of II Naomori and become his adopted son-in-law, and this Naotora's wife is thought to be the person who has traditionally been identified as Jiro-hoshi or Naotora (posthumous name Myoun-in-den Tsukifune Yuen-dai-shi). Researchers from
Hikone Castle Museum also deemed the "Ii clan biography" which contains the theory about Ii Naotora being female as unreliable as it was based on folklore and not actual historical records. Atsuyuki Wakabayashi from
Shizuoka University has stated that the letter was co-signed between Jirō Hōshi and Sekiguchi Naotora as an imperial edict. Ii Tatsuo, the director of the Ii clan Museum in
Kyoto which preserved those documents, also favored this explanation that Ii Naotora was not a woman named Jirō Hōshi, but instead a male retainer of the Imagawa clan named Sekiguchi Ujitsune, who had been bestowed the fiefdoms of the Ii clan. The Hachisaki temple in
Shizuoka Prefecture claimed that they have the replica of the letter dated from 1566 that pointing out the relationship between Naotora with said Sekiguchi clan. • The theory of Ii Naotora being descendant of the Sekiguchi clan was further expanded as recent Ii museum researchers have found out the supplementary document from "Kawate clan Genealogy" has revealed that before Sekiguchi's appointment as "Ii Naotora", the Ii clan was temporarily handled by Kawate Suisuke Kagetaka, a vassal of the
Matsudaira (Tokugawa) clan. This version explains how after Niino Samanosuke, (Naomasa's benefactor who had invited him to Iinoya), was killed in battle in 1564, Kagetaka assisted Naotora and Jirō Hōshi, and it was thought that around this time he changed his surname from Kawate to Ii. At some point of his service within the Ii clan, Kagetaka refused to implement a decree from
Imagawa Ujizane as he argued that the decree was not beneficial for the for Ii clan's interests. However, when he was pressured by Sekiguchi Echigo-no-kami Ujitsune (Sekiguchi Naotora's father), to carry out the decree (August 1668, letter from Sekiguchi Ujitsune), Kagetaka reluctantly accepted the decree. However, this incident caused him to be estranged from the Ii clan. At the sametime Iinoya was invaded by Tokugawa Ieyasu, who had just declared his independence from the Imagawa clan, and it was believed that Kagetaka immediately sided with Ieyasu and ended up driving out Naotora from
Hikone Castle. Afterwards, Kagetaka did not return to serve
Ii Naomasa, although Naomasa began to serve Ieyasu, but his son Yoshinori (Suisuke) served Naomasa. It was believed that by this time he had already reverted to his original surname, Kawate. • Miwa Mori, a professor of early modern history at
Kyoto Women's University, also supported the theory of which released by the institution Ii Museum's statement, which was traced from a record of a written retainer of the Ii clan named Kimata in 1640. Mori stated this source as highly reliable primary source. Similarly,
Daimon Watanabe, a history professor from
Bukkyo University, also rejected the supplementary sources of
Moriyasu Kō shoki about the female Naotora theory, as he says the scripts were copied from an unverified
Edo period book. 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. Daimon also added that while a woman could become head of clan in certain situations, it was an extremely rare case, and Naotora was unlikely to be one of them. Other modern researchers who have similar view with Motoki Kuroda's theory that Naotora is the son of Sekiguchi Ujitsune with childhood name of Jiro Hoshi are
Shiba Hiroyuki,
Masanori Suzuki, and Yukihiro Kasuya.
Female Naotora theory There is only one contemporaneous document related to the person named "Ii Naotora" (井伊直虎) that she is believed to be the same person as Jirō Hōshi (次郎法師), the daughter of
Ii Naomori (井伊直盛), who became the head of the Ii family despite being a woman. This theory is based on the "Ii Family Chronicle" (井伊家伝記), written in the mid-Edo period in 1730 (Kyōhō 15). It is said that Jirō Hoshi was engaged to
Ii Naochika (井伊直親) but remained unmarried throughout her life and was the foster mother of Naochika's orphaned child,
Ii Naomasa (井伊直政), who later became one of Tokugawa's Four Heavenly Kings.
Tetsuo Owada, a professor emeritus of Sengoku history at
Shizuoka University who published a book about Naotora has said that this theory of misidentification of
Ii Naotora is quite possible, since for generations, many of the heirs of Ii clan usually being called "Jiro", thus the name is suspected as just a pseudonym of various historical figures, although he did not deny the possibility that Ii Naotora was a daughter of Ii Naomori, a leader of Iinoya-is a part of
Tōtōmi, who had been defeated by
Imagawa Yoshimoto and became a vassal of Imagawa. According to this theory, as Ii clan had no male heir, so Naotora's great uncle
Ii Naomitsu tried to betroth his son
Ii Naochika to her so that he could inherit the clan. Unidentified
Imagawa clan retainers carried a report of the plans to Imagawa, who ordered Naomitsu and his son Naochika to commit
seppuku. Naomitsu died, but Naochika, who was very young, was protected by a Buddhist priest named Nankei. Naochika managed to flee to
Shinano. Naotora became a priestess, and was named Jiro-Hoshi aged ten by Nankei. In 1563,
Ii Naohira and other men from Ii clan were ordered to break into
Hikuma Castle as proof of their loyalty to the Imagawa.
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. On September 18, Otazu no Kata then poisoned Naohira's tea and he died soon after. Following Naohira's death, Jiro Hoshi returned to secular life the male name Naotora and declared herself the nominal head of the
Ii clan. It was recorded that Naotora, being a former nun, often acted to avoid battles, earning the respect of many civilians. She was responsible for the development of agriculture and the substantial expansion of the domains of her clan in the region of Enshū.
Synthesis theory Michifumi Isoda, professor of
International Research Center for Japanese Studies instead offered a synthesis theory which differ from the "Ii clan Biography", that both female Jirō Hōshi and male Ii Naotora both existed as different person, and became head of Ii clan on different occasions. Isoda offered this explanation based on the correspondence material from
Seto Hokyu, a samurai under Ii clan, with the Imagawa clan, where the Imagawa recognized Jirō Hōshi as head of Ii clan in September 1568. However, after the Imagawa clan fall and the entrance of Tokugawa clan in the area on December, the name of Ii Naotora emerged as the head of Ii clan, thus Isoda suspected that the Tokugawa clan deposed Jirō Hōshi and installed Naotora as the head of Ii clan instead. Meanwhile, professor Hirofumi Yamamoto from
University of Tokyo giving his chronological concilliatory explanation regarding the letter co-signed by Jiro-Hoshi (daughter of Ii Naomori) and Sekiguchi Naotora (son of Ujitsune) that it indicated while Jiro-Hoshi inherited the Ii clan's surname, the official
de facto control of Ii clan's territories including Iinoya castle was run by Naotora, until Ii Naomasa become old enough to inherit the position of Ii clan's leader. == Biography ==