was a senior retainer beneath the clan of Toyotomi

Toyotomi clan

Originating in Owari Province, the served as retainers to the Oda clan throughout 16th-century Japan's Sengoku period. -Unity and Conflict:The most influential figure within the Toyotomi was Toyotomi Hideyoshi, one of the three "unifiers of Japan." Oda Nobunaga was another primary unifier and the...

 throughout the latter Sengoku Period

Sengoku period

The or Warring States period in Japanese history was a time of social upheaval, political intrigue, and nearly constant military conflict that lasted roughly from the middle of the 15th century to the beginning of the 17th century. The name "Sengoku" was adopted by Japanese historians in reference...

 of Feudal Japan. Hidemoto was the eldest son of Mōri Motokiyo

Mori Motokiyo

was the fourth son to the reputed Mōri Motonari throughout the latter Sengoku Period of Feudal Japan....

 and initially began service under the Toyotomi at the time at which he was of the age to become a military commander under his cousin Terumoto

Mori Terumoto

Mōri Terumoto , son of Mōri Takamoto and grandson and successor of the great warlord Mōri Motonari, fought against Toyotomi Hideyoshi but was eventually overcome, participated in the Kyūshū campaign on Hideyoshi's side and built Hiroshima Castle, thus essentially founding Hiroshima.Terumoto was a...

, the head of the Mōri clan

Mori clan

The Mōri clan was a family of daimyō, descended from Ōe no Hiromoto and established themselves in Aki Province. Their name was derived from a shōen in Mōri, Aikō District, Sagami Province. The generation of Hiromoto began to name themselves Mōri.After the Jōkyū War, Mōri was appointed to the jitō...

. Within the year of 1597, Hidemoto became a highly redeemed figure beneath the Mori, and, by variable means, was chosen specifically by Toyotomi Hideyoshi

Toyotomi Hideyoshi

was a daimyo warrior, general and politician of the Sengoku period. He unified the political factions of Japan. He succeeded his former liege lord, Oda Nobunaga, and brought an end to the Sengoku period. The period of his rule is often called the Momoyama period, named after Hideyoshi's castle...

 to lead the Second Invasion of Korea's Army of the Right, where he respectively wielded 30,000 soldiers. Hidemoto was additionally backed by six generals that were assigned to his right wing: Katō Kiyomasa

Kato Kiyomasa

was a Japanese daimyō of the Azuchi-Momoyama and Edo period.-Origins and early career:Kiyomasa was born in Owari Province to Katō Kiyotada. Kiyotada's wife, Ito, was a cousin of Toyotomi Hideyoshi's mother. Kiyotada died while his son was still young...

, who possessed 10,000; Kuroda Nagamasa

Kuroda Nagamasa

was a daimyo of Japan. He was the son of Kuroda Kanbei.In 1577, When Nagamasa was a small child, his father was condemned as a spy by Oda Nobunaga. Nagamasa was kidnapped and nearly killed as a hostage. Takenaka Hanbei ended up rescuing him....

, who wielded 5,000; Nabeshima Naoshige

Nabeshima Naoshige

a retainer of the Ryūzōji clan during the Sengoku period of the 16th century. Naoshige was the son of Nabeshima Kiyosada and was known as Nobumasa throughout half of his career under the Ryūzōji. Naoshige proved himself as being one of the greatest generals under Ryūzōji Takanobu...

 with 12,000; Ikeda Hideuji tasked with 2,800; Chōsokabe Motochika

Chosokabe Motochika

was a Sengoku period daimyo in Japan. He was the 21st chief of the Chōsokabe clan of Tosa Province . He was the son and heir of Chōsokabe Kunichika and his mother was a daughter of the Saitō clan of Mino Province....

, who wielded 3,000; and a certain Nakagawa Hidenari

Nakagawa Hidenari

' was a Japanese daimyo in the Azuchi-Momoyama to Edo period. He was the 2nd son of Nakagawa Kiyohide.In 1582, Kiyohide died in the Battle of Shizugatake and Hidenari's brother Hidemasa succeeded to the family headship. However, Hidemasa died young in 1592 and Hidenari succeeded to the house and...

, who respectively possessed 2,500. With these preparations thus made, Hidemoto and his mutual supporters led the initial Japanese offensive within the Korean province of Gyeongsang, where they marched towards Jeonju

Jeonju

Jeonju is a city in South Korea, and the capital of Jeollabuk-do, or North Jeolla Province. It is an important tourist center famous for Korean food, historic buildings, sports activities and innovative festivals.- History :...

 after assaulting Busan

Busan

Busan , formerly spelled Pusan is South Korea's second largest metropolis after Seoul, with a population of around 3.6 million. The Metropolitan area population is 4,399,515 as of 2010. It is the largest port city in South Korea and the fifth largest port in the world...

, presently taking both Sacheon

Sacheon

Sacheon is a city in South Gyeongsang Province, South Korea. Sacheon's chief fame comes from its being the site of two naval battles in the Seven Year War....

 and Changpyong. Following this campaign, Hidemoto obtained a far greater sum of power beneath him, justifiably by means of becoming the governor over the provinces of Suo

Suo Province

was a province of Japan in the area that is today the eastern part of Yamaguchi Prefecture. It was sometimes called . Suō bordered on Aki, Iwami, and Nagato Provinces....

 and Nagato

Nagato Province

, often called , was a province of Japan. It was at the extreme western end of Honshū, in the area that is today Yamaguchi Prefecture. Nagato bordered on Iwami and Suō Provinces....

, which he held up until the decisive Sekigahara Campaign of 1600.

Initially within this campaign, Hidemoto was determined to rationally support the forces of Tokugawa Ieyasu

Tokugawa Ieyasu

 was the founder and first shogun of the Tokugawa shogunate of Japan , which ruled from the Battle of Sekigahara  in 1600 until the Meiji Restoration in 1868. Ieyasu seized power in 1600, received appointment as shogun in 1603, abdicated from office in 1605, but...

--dubbed as the 'east'--and as his cousin, Terumoto, possessed 128,000 soldiers that he would use to mutually back the Western forces of Mitsunari, Hidemoto, intending on assisting the Eastern forces of Ieyasu, gathered his armaments with great immediacy, equipping himself with 15,000 soldiers and stationed his entire army on Mt. Nangu, where his generals were equally distributed along the eastern borders of this mountain. To make the circumstances go from beneficial to entirely detrimental, Kikkawa Hiroie

Kikkawa Hiroie

' was a Japanese daimyo of the Azuchi-Momoyama period through early Edo period.Hiroie's father was Kikkawa Motoharu and his mother was a daughter of Kumagai Nobunao. He initially was named Tsunenobu and made his debut on the battle field on 1570 against Amago Katsuhisa with his father...

, General of Hidemoto, refused to move against the Eastern forces during the battle's beginning; and as Hiroie was the leading general of the army, Hidemoto was restricted from ascending to the frontlines, placing him with little other choice than to resentfully retreat without offering his mutual support to the Tokugawa. And as a general resolution to such an event, Hidemoto's initial fief was dropped from 200,000 to a moderate 50,000 out of sympathetic consideration to Terumoto's service, causing Hidemoto a justifiable level of humiliation. Regardless, Hidemoto surmisably remained as a primary commander under Ieyasu throughout the Period of Edo

Edo period

The , or , is a division of Japanese history which was ruled by the shoguns of the Tokugawa family, running from 1603 to 1868. The political entity of this period was the Tokugawa shogunate....

, where he more than likely assisted within the Sieges of Osaka and the later Shimabara Rebellion

Shimabara Rebellion

The was an uprising largely involving Japanese peasants, most of them Catholic Christians, in 1637–1638 during the Edo period.It was one of only a handful of instances of serious unrest during the relatively peaceful period of the Tokugawa shogunate's rule...

 before eventually dying during the year of 1650.