Yoshitsugu Otani (1537-21 October 1600), also called Keimatsu Otani, was a general of the Toyotomi clan and the daimyo of the Otani clan. Loyal to Hideyoshi Hashiba, he became one of his most loyal followers and fought for the Western Army as Mitsunari Ishida's most trusted general. He died in battle due to betrayal by his allies, but was a respected man who had chronicled many events in history: from the Genpei War to the Sengoku Period.
Yoshitsugu Otani was the son of a servant to the Otomo clan, and was known for his leprosy as well as his friendship. He was originally a yoriki (helper) for Mitsunari Ishida during the 1570s and became known as a fine strategist. Hideyoshi Hashiba, the superior of Mitsunari, made him his general, and he fought loyally in the Battle of Shizugatake in 1583 and the battles that followed such as Komaki-Nagakute.
In 1585, after Hideyoshi became the Shogun, ruler of all Japan, Yoshitsugu became the Minister of Justice (Gyobu-shoyu), and he also held military command; in the 1587 Kyushu Campaign he commanded 18,000 troops. He proceeded to fight in the Fall of Odawara campaign against the Hojo in 1590 and with Nagamori Mashita and Mitsunari was sent to Korea as one of the Three Bureaucrats during the Japanese invasions of Korea. After the death of Hideyoshi in 1598 the Japanese army in Korea returned home, and Yoshitsugu backed Mitsunari Ishida's bid for the shogunate.
During the Battle of Sekigahara, Yoshitsugu Otani was dispatced to keep a watchful eye on Hideaki Kobayakawa, Yasuharu Wakisaka, and Hiroie Kikkawa, who were likely to defect. But when Masanori Fukushima, the Tokugawa general charged out at Yukinaga Konishi, he left his post and the three generals were able to defect. Yoshitsugu sensed defeat and stabbed himself with a cross spear while his sub-officer Gosuke beheaded him. He died a hero, having narrated various tales about the Genpei War and the Sengoku Period.