Tomo no Yoshio (伴善男)
He was believed to be born in Sado Province while his father Kunimichi was exiled to that island.
(According to "Nihon Sandai Jitsuroku" (lit. the True History of Three Reigns of Japan), Yoshio was born in Kyoto in 805 when his father Kunimichi had already been pardoned and returned to Kyoto, but another story in the "Tale of Ujishui" says that Yoshio was originally a servant of gunji (the local administrative official) of Sado and was later adopted by the Otomo clan.)
In 823, the Otomo clan changed their name to Tomo to avoid a conflict with Emperor Junna's name Otomo.
It was said that Yoshio was fine-looking by nature as well as cunning and calculating. He had sunken eyes, had long whiskers, was short in height, was arrogant, and avoided socializing with people. He was eloquent, had insight, was decisive, and was an expert in administrative affairs, but lacked generosity and elegance and was cruel.
In 830, he had a post in the Kyoshoden (an archive building in the Imperial Palace precincts) and came to know Emperor Ninmyo. In 841, he assumed Dainaiki (a post in charge of document management). In 842, he was appointed Kurodo (Officer of the Imperial Court Affairs Office) and Shikibu taijo (Senior Secretary of the Ministry of Ceremonial). In 843, he was promoted to Jugoinoge (Junior Fifth Rank, Lower Grade) and assigned as Gon no kami (official title of local governor) of Sanuki Province and benkan (an official in the Department of State).
In 846, he challenged Sadaiben (Major Executive Officer of the Left) Masamio on the principle of law at the time of the Case of Priest Zengai and brought down five of his co-worker benkan, including Masamio. During those days, he asserted that it was unfair not to return to the Otomo family the paddy fields covering an area of about 10.9km in the Province of Kaga, which had been formerly owned by the Otomo family but confiscated and incorporated into the Kangakuden, state paddy fields to produce food for bureaucrat trainees, following the murder case of FUJIWARA no Tanetsugu; although OTOMO no Yakamochi was acquitted, and had the paddy fields forcibly returned to the Otomo family according to IkenJunikajo (lit. Twelve Opinions) by Kiyoyuki MIYOSHI.
In 847, he was promoted to Jugoinojo (Junior Fifth Rank, Upper Grade) and appointed as Kurodo no to (Head Chamberlain) and Uchuben (Deputy-Major Executive Officer of the Right). In 848, he was further promoted to Jushiinoge (Junior Forth Rank, Lower Grade) and assumed Sangi (councillor) and Udaiben (Major Executive Officer of the Right). In 849, he took such posts as Uemon no kami (Captain of the Right Division of Outer Palace Guards), Sangi, and Shikibu no taifu (Senior Assistant Minister of the Ministry of Ceremonial), while being further promoted to Jushinojo (Junior Fourth Rank, Upper Grade). In the same year, he took the posts of Shimotsuke no kuni no kami (the governer of Shimotsuke Province) and Kebiishi no betto (Superintendent of the Imperial Police). In 850, he assumed Kotaigo gu no daibu (Master of the Empress Dowager's Household). In 851, he also assumed the post of Mimasaka no kuni no kami (governor of Mimakasa Province). In 853, he was promoted to Shoshiinoge (Senior Fourth Rank, Lower Grade) and also served as Chugu daibu (Master of the Consort's Household). In 854, he also assumed Sanuki no kami (the governor of Sanuki Province). In 855, he was promoted to Jusanmi (Junior Third Rank). He was engaged in editing of "Shoku Nihonkoki" (an official history text of Japan), together with Udaijin (Minister of the Right) FUJIWARA no Yoshifusa and others.
In 859, he was promoted to Shosanmi (Junior Third Rank) and served as Minbukyo (Minister of Popular Affairs). In 860, Chunagon (vice-councilor of state). In 864, promoted to Dainagon (chief councilor of state). It was the first time anybody from the Tomo (Otomo) clan reached to the post of Dainagon since OTOMO no Tabito did back in 730, and Yoshio reached the highest rank ever achieved by the family.
In March (leap month) of 866, the Otemon Gate was set on fire, and Yoshio accused Sadaijin (Minister of the Left) Genshin of being the arsonist. Then, the situation became tense as Genshin's residence was put under siege, but as Daijo daijin FUJIWARA no Yoshifusa talked Emperor Seiwa into believing the innocence of Genshin, he was judged innocent. In August, somebody informed that the fire of the Otenmon Gate was caused by Yoshio and his son Nakatsune, and Yoshio denied his involvement in the case despite being tortured. He was eventually sentenced to death (according to the Ritsuryo code) despite his denial, but the death penalty was replaced by deportation because of his loyalty to the late Emperor Ninmyo; he kept holding an annual memorial service for the late Emperor to return the favor of the Emperor who first recognized him. Yoshio was exiled in Izu Province, his son Nakatsune to Oki Province, and many of the Tomo clan and Ki clan were sentenced to deportation (Otenmon Incident).
In 868, Yoshio passed away in exile at Izu.