I thing I might have posted part of this before in this subreddit, I'm not sure... Anyway, Japan was strongly influenced by Tang China soon before it decided (and then became to busy fighting with itself) cutting ties. It is during the Nara and Heian periods when the Japanese court system starts adapting Chinese models and the figure of the Emperor/tenno is developed.

After Heian-kyo became the centre of Imperial power (indeed with an urban structure copied from the Tang capital), Emperor Kanmu (737-806) and his successor, Saga, initiated a campaign to strengthen the power of the Imperial institution, establishing new governmental offices based on Chinese models, and sponsoring the creation of new branches of Buddhism. Their plan was to make Chinese ideas, particularly the Confucian notion of an all-powerful sovereign, widespread in court circles. They sent missions to the continent with the intention of gaining a better knowledge of continental Buddhist currents, imported books and art, and basically established Tang China as a cultural model to imitate.

Politically speaking, Buddhism had become an important tool for Japanese Emperors who declared themselves "the body of the nation" Buddhist monasteries prayed for, which might explain why they weren't particularly keen to keep in contact with the Tang court after the Chinese government suppressed this religion in 845 (I know next to nothing about Chinese history, I'm sorry if I generalize). Finally, as the political situation in the continent got worse, the ambassador Sugawara no Michizane, appointed in 894, requested the cessation of embassies. A state that would remain unchanged for centuries. It is at this point when the court experiences a sort of artistic and literary "nativist revival" that will set the grounds for an idea of purely "Japanese" culture. However, this classical Japanese archetypes were created by authors whose education included a Tang background that doesn't just disappear into nothing; it keeps being very culturally relevant. For instance, the Genji Monogatari, the Japanese literary work, which would become highly influential, is in turn influenced by Bai Juyi's Song of Everlasting Sorrow and so on.

Also, I'm not so sure about white make-up or kimono coming from Tang influences. I'm pretty sure the white faces come from Heian courtiers (although again, that could be indirectly Tang).

Sources: Borgen, Robert. “The Politics of Classical Chinese in the Early Japanese Court” in Knechtges, David R. and Vance, Eugene ed. Rhetorics and the Discourse of Power in Court Culture: China, Europe, and Japan.

Pollack, David. "The Informing Image. 'China' in Genji Monogatari" in Monumenta Nipponica, Vol. 38, No. 4.

Edit: words.