Uesugi Kenshin in the context of "Avatar"

The Sengoku period (戦国時代, Sengoku jidai; Japanese pronunciation: [seŋ.ɡo.kɯ (d)ʑiꜜ.dai, -ŋo.kɯ-] lit. 'Warring States period') was the period in Japanese history in which civil wars and social upheavals took place almost continuously in the 15th and 16th centuries. The Kyōtoku incident (1454), Ōnin War (1467), or Meiō incident [ja] (1493) are generally chosen as the period's start date, but there are many competing historiographies for its end date, ranging from 1568, the date of Oda Nobunaga's march on Kyoto, to the suppression of the Shimabara Rebellion in 1638, deep into what was traditionally considered the Edo period. Regardless of the dates chosen, the Sengoku period overlaps substantially with the Muromachi period (1336–1573).

This period was characterized by the decline of the Ashikaga shogunate, the de facto central government, while the sengoku daimyo (戦国大名, feudal lords of the Sengoku period), local power-holders, acquired greater political influence. The people rebelled against the feudal lords in revolts known as Ikkō-ikki (Ikkō-shū uprising).

The Battles of Kawanakajima (川中島の戦い, Kawanakajima no tatakai) were a series of battles fought in the Sengoku period of Japan between Takeda Shingen of Kai Province and Uesugi Kenshin of Echigo Province from 1553 to 1564. Shingen and Kenshin contested each other for control of the plain of Kawanakajima between the Sai River and Chikuma River in northern Shinano Province, located in the present-day city of Nagano. The battles were triggered after Shingen conquered Shinano, expelling Ogasawara Nagatoki and Murakami Yoshikiyo, who subsequently turned to Kenshin for help.

Five major battles of Kawanakajima occurred: Fuse in 1553, Saigawa in 1555, Uenohara in 1557, Hachimanbara in 1561, and Shiozaki in 1564. The most famous and severe battle was fought on 18 October 1561 in the heart of the Kawanakajima plain, thus being known the Battle of Kawanakajima. The battles were ultimately inconclusive and neither Shingen nor Kenshin established their control over the plain of Kawanakajima.

The Uesugi clan (上杉氏, Uesugi-shi, historically also Uyesugi) is a Japanese samurai clan which was at its peak one of the most powerful during the Muromachi and Sengoku periods (14th to 17th centuries). At its height, the clan had three main branches: the Ōgigayatsu, Inukake, and Yamanouchi. Its most well-known member is the warlord Uesugi Kenshin (1530–1578).

During the Edo period, the Uesugi were a tozama or outsider clan, in contrast with the fudai or insider daimyō clans which had been hereditary vassals or allies of the Tokugawa clan.

Murakami Yoshikiyo (村上 義清, 1501–1573) was a Japanese samurai from the Murakami clan and retainer of the Uesugi clan during the Sengoku period of the 16th century. Yoshikiyo followed in fighting against both Takeda Nobutora and his son Takeda Shingen. Yoshikiyo was also a very close ally under Uesugi Kenshin and one of Shingen's bitterest opponents for his high kill-counts in their conflicts.

Before Murakami came into conflict with Takeda, they had good diplomatic relations as Yoshikiyo had sent back Oi Sadataka, a common enemy of both Murakami and Takeda when he was captured in Murakami's domain back to Takeda's base city of Kōfu as a prisoner for execution.

Bonsai (/ˈbɒnsaɪ/; Japanese: 盆栽, lit. 'tray planting', pronounced [boɰ̃sai] ) is the Japanese art of growing and shaping miniature trees in containers, with a long documented history of influences and native Japanese development over a thousand years, and with unique aesthetics, cultural history, and terminology derived from its evolution in Japan. Similar arts exist in other cultures, including Korea's bunjae, the Chinese art of penjing, and the miniature living landscapes of Vietnamese Hòn non bộ.

The loanword bonsai has become an umbrella term in English, attached to many forms of diminutive potted plants, and also on occasion to other living and non-living things. According to Stephen Orr in The New York Times, "[i]n the West, the word is used to describe virtually all miniature container trees, whether they are authentically trained bonsai or just small rooted cuttings. Technically, though, the term should be reserved for plants that are grown in shallow containers following the precise tenets of bonsai pruning and training, resulting in an artful miniature replica of a full-grown tree in nature." In the most definitive sense, "bonsai" refers to miniaturized, container-grown trees adhering to Japanese bonsai tradition and principles.