Korea

According to the History of the Three Kingdoms, Silla adopted the clothing and customs of the Tang dynasty as a way of transforming its people from "barbarians" into "Hwa" (華):

[...] Gim Chun-chu entered the Tang dynasty, requested for [the right to] adopt Tang customs. The Emperor Taizong [of Tang] issued an edict in approval and bestowed [upon Gim Chun-chu] clothes and belts. [Gim Chun-chu] thus returned [to Silla] and enforced [Tang clothing and customs], thereby transforming barbarians into Hwa. Four years into the reign of King Munmu [of Silla], the clothing [style] of women was once again adjusted. The clothing and headwear [of Silla] became the same as those of Jungguk ever since.^[12]

In the Ten Articles for Instruction, the King Taejo of Goryeo expressed his wish for the Goryeo dynasty to follow the example of the Emperor Yao and highlighted the influence of the Tang dynasty on Korea:

[...] while succession to the throne by one's eldest legitimate issue should be the rule, Yao abdicated in favor of Shun, for Danzhu was unworthy [of the throne]; this was indeed putting the interests of the state [ahead of one's personal feelings]. If the eldest legitimate son is unworthy [of the throne], let the second eldest succeed to the throne; if the second eldest, too, is unworthy [of the throne], select the brother the people consider the best qualified for the throne.^[13][14]

[...] we the Orient, for our admiration for the ways of the Tang dynasty, have emulated its writings, objects, rites and music.^[15][16]

The King Injong of Goryeo once issued an edict that urged the Koreans to discard the ways of the Khitan "barbarians" in favor of Chinese traditions:

[...] replicate and follow the ways of Hwaha, forbid the traditions of the Khitan barbarians [...]^[17]

The Veritable Records of the Joseon Dynasty labelled Korea as "Sojunghwa" (小中華) and highlighted the relations between China and Korea:

Ever since Jizi arrived in the East, [his] enlightenment became widespread; males exhibited the qualities of martyrs, while females were chaste and upright; [hence Korea is] known in historiography as 'Sojunghwa'.^[18]

"Ever since Jizi was enfeoffed, every [Korean] dynasty has been regarded as part of the realm [of China]. The Han dynasty established four commanderies [on the Korean Peninsula], while the Tang dynasty established an additional Fuyu Commandery. During the [extant] Ming dynasty, all eight provinces [of the Joseon dynasty] are placed under [the administration of] Liaodong; all [Joseon] clothing, headwear, writings and objects follow the style of Hwa; [the Ming dynasty] conferred upon the [Joseon] king a seal, appointing him [the responsibility of] governance [...]^[19]

The court-commissioned Comprehensive Mirror of the Eastern State by Seo Geo-jeong highlighted the Chinese influence on Korea:

All [Joseon] clothing and institutions mirror that of Jungguk, thus [the Joseon dynasty] is known as 'the state of poetry, books, rites and music', and 'the state of benevolence and righteousness'; these were introduced by Jizi, so how could these be untrue!^[20]

In the 17th century, when the Manchu-led Qing dynasty replaced the Han-led Ming dynasty as the ruling dynasty of China proper, the Joseon dynasty believed that the Qing dynasty was unworthy of succeeding the politico-cultural orthodoxy of "China". Instead, the Confucianist Joseon dynasty asserted itself as the legitimate heir to the Chinese civilization and termed itself "Little Central Kingdom".^[1] In 2010, scholar Brian Reynolds Myers stated in reference to the move that:

[T]he national identities of literate Koreans and Chinese [were] mutually indistinguishable. Believing their civilization to have been founded by a Chinese sage in China's image, educated Koreans subscribed to a Confucian worldview that posited their country in a position of permanent subservience to the Middle Kingdom. Even when Korea isolated itself from the mainland in the seventeenth century, it did so in the conviction that it was guarding Chinese tradition better than the Chinese themselves.^[21]

Sojunghwa is closely related to the classical sadaejuui.^[22]

Vietnam

Numerous Vietnamese dynasties attempted to replicate the Chinese tributary system in Southeast Asia, whilst maintaining tributary relations with Chinese dynasties.^[23] Vietnamese monarchs of multiple dynasties adopted the imperial title "hoàng đế" (皇帝; "emperor") domestically, but reverted to the royal title "vương" (王; "king") when dealing with China—a policy known as "emperor at home, king abroad". On many occasions, some Vietnamese monarchs styled themselves as the "Central Kingdom" or "Central State" and referred to various Chinese dynasties as "Bắc Triều" (北朝; "northern dynasty") in relation to Vietnam, self-styled as "Nam Triều" (南朝; "southern dynasty").^[24] In 1010, Lý Thái Tổ issued the Edict on the Transfer of the Capital that likened himself to Chinese monarchs who initiated the relocation of the capital, effectively positioning the Lý dynasty within the politico-cultural realm of China:

In the old days, until [the reign of] Pan Geng, the Shang dynasty shifted [its capital] five times; until [the reign of] the King Cheng [of Zhou], the Zhou dynasty relocated its capital three times. How could the monarchs of the Three Dynasties [of Ancient China] who moved [their capitals] be motivated by personal gains? They did so [out of a desire] to expand their territories or [in search of] a centralized location [for better governance], all for the good of the people.^[25]

The Complete Annals of Đại Việt used "Trung Quốc" (中國) to refer to Vietnam:

[...] [the Lý dynasty] once again launched a massive attack on the Song dynasty in the Qin Prefecture and the Lian Prefecture, with the intent of rescuing the people of Trung Quốc afflicted by Song's implementation of the Green Sprouts Law.^[26]

[...] [Lý Nhân Tông] ordered Lý Thường Kiệt to launch a campaign against Champa. At the start, Lý Giác fled to Champa and disclosed information on Trung Quốc [...]^[27]

Amidst Hồ's usurpation of the Trần throne, the Ming dynasty [launched] a southward invasion, annexed our territories, subjugated our people, [enforced] strict laws and punishments, [implemented] heavy taxes and labor. The heroic individuals of Trung Quốc frequently feinted as [submissive] officials [of the Ming dynasty] to keep the North at ease.^[28]

Lê Thái Tổ once issued an edict that adopted "Trung Quốc" (中國) as an alternative name for Vietnam:

The [Ming] larcenists were in Trung Quốc, [the livelihood of] the people were still unstable, did you have a peace of mind? Previously [when] the Hồ clan was immoral, the [Ming] larcenists thus seized our country. The abuses [perpetuated by the Ming dynasty] were witnessed by all.^[29]

In 1470, in preparation for his invasion of Champa, Lê Thánh Tông issued an edict which referred to the Later Lê dynasty and earlier Vietnamese regimes as "Trung Quốc" (中國):

Since ancient times, barbarians have posed a threat to Trung Quốc; thus the sage-king embarked on military campaigns to deter all under Heaven.^[30]

In 1479, Lê Thánh Tông issued an edict to justify his invasion of Muang Phuan. In the edict, "Trung Hạ" (中夏) was used to refer to the Later Lê dynasty:

I [intend to] follow the pioneering steps of my ancestors, propagate and implement a magnificent plan, rule over Trung Hạ, pacify the outer barbarians.^[31]

The Nguyễn dynasty considered itself the legitimate heir to the Chinese civilization.^[32] Gia Long Đế once used "Trung Quốc" (中國) and "Hạ" (夏) to refer to the Nguyễn and earlier Vietnamese dynasties:

Trung Quốc vis-à-vis the outer barbarians [is akin to] the [properly] governed vis-à-vis the ungoverned [...]^[33]

The late king governed all under Heaven [by adhering to the principle that] Hạ should not intermix with the barbarians [...]^[34]

The Imperially-commissioned Annotated Text Reflecting the Complete History of Việt referred to the Nguyễn dynasty as "Thần Châu" (神州):

Until the numerous sages of our dynasty laid the foundation in the South, our Thế Tổ, the Emperor Cao, pacified Thần Châu and ruled over the entirety of Việt, [with Nguyễn territories] bordering the sea to the east, Yunnan to the west, the Khmer barbarians to the south and Liangguang to the north. The expansiveness of [Nguyễn] territories was hitherto unmatched [by prior Vietnamese dynasties].^[35]

In the Poems on the Way to Min, Lý Văn Phức (a descendent of Ming Chinese refugees) escorted some stranded Chinese sailors back to Fujian province. However, when he arrived there, the guesthouse where he was supposed to stay had a sign over it which indicated that it was for "barbarians." Lý Văn Phức defended his position with an essay that highlighted that Vietnam followed the ways of China without the Manchurian influences of the 17th century and therefore should be considered "Hoa" (華):

In terms of governance and law, [Vietnam] follows [the ways of] the Two Emperors and Three Kings [of Ancient China]; in terms of [Confucian] orthodoxy, [Vietnam] adheres to [the teachings of] the Six Classics and Four Books, and subscribes to the schools of thought of Confucius, Mencius, Cheng Hao, Cheng Yi and Zhu Xi. In terms of knowledge, [Vietnam] consults The Commentary of Zuo, Discourses of the States and [the works of] Ban Gu and Sima Qian; in terms of writings, [Vietnamese] poetries and rhapsodies imitate [the styles of] the Selections of Refined Literature and that of Li Bai and Du Fu; in terms of calligraphies and paintings, [Vietnamese works] emulate [the styles of] the Rites of Zhou and the Six Methods and that of Zhong Yao and Wang Xizhi. [The procedures of] selecting the virtuous for government positions [in Vietnam have their roots in] the Han and Tang dynasties; the belts and headwear [of Vietnam originate from] the clothing [styles] of the Song and Ming dynasties. Since [Vietnam] follows the ways [of China], yet if [China considers the Vietnamese] as barbarians; how, then, do you define the meaning of Hoa?^[36]

Japan

Fujiwara no Hirotsugu once presented a memorial to the throne, referring to Japan as "Chūgoku" (中國) and adopted the Chinese worldview of treating surrounding ethnic minorities as "barbarians":

The northern barbarians Emishi and the western barbarians Hayato, [with] natural dispositions [akin to] wolves, revolt easily and whose wild ambitions cannot be easily tamed. Since ancient times, [whenever] Chūgoku has sages, [the barbarians] would subsequently submit; [whenever] the court experiences [political] instability, [the barbarians] would rebel at the earliest opportunity [...]^[37]

The Chronicles of Japan used "Chūgoku" (中國) to refer to Japan:

[...] Silla refused to submit to Chūgoku.^[38]

The Extended Chronicles of Japan referred to Japan as "Chūgoku" (中國):

This [marked] the start of contact between the Tokan Island and Chūgoku.^[39]

When the Empress Genmei yielded the throne to the Empress Genshō, Japan was referred to as "Kaka" (華夏) in an edict issued by the former:

[Her] wisdom, lenience and kindness [are] bestowed by Heaven. [She is] placid and personable. Kaka [will last] an eternity. [She is] widely praised. Today, the imperial throne [will be] passed to the princess.^[40]

After the Qing dynasty had replaced the Ming dynasty in China proper, Japanese scholars declared that the Qing dynasty did not have the legitimacy to represent the politico-cultural realm of "China" whilst simultaneously explicitly identifying Japan as "China". In Kai Hentai by Hayashi Gahō and Hayashi Hōkō, it was argued that Japan had replaced the Qing dynasty as the center of Chinese civilization.^[41] In Chūchō Jijitsu by Yamaga Sokō, "Chūchō" (中朝; used in a similar sense as "Middle Kingdom"), "Chūka" (中華) and "Chūgoku" (中國) were adopted as alternative names for Japan, while "Gaichō" (外朝; "outer dynasty") was used to refer to the Qing dynasty.^[42]

During the Meiji Restoration, the Emperor Meiji once issued an edict that referred to Japan as "Ka" (華):

[There is a] need to urgently rectify the nominal relations between the monarch and the officials, to make clear the distinctions between Ka and the barbarians and between the inner and outer domains, so as to uphold the cardinal principles of all under Heaven.^[43]