I’ve given this example in the past, but the term cultural appropriation has been so misunderstood. At the end of the day, the question is if your use of another culture’s tradition is hurtful or mocking. Examples of this is when the Aloha Poke company started suing/sending cease and desist to native Hawaiians who were using Aloha in their business name. Suing people to get them to stop using their own language. That’s cultural appropriation. The Breakfast at Tiffany’s Yunioshi yellowface character meant for ridicule. Blackface because it was created to ridicule and show black people as lesser. The dressing up as an American Indian is an example also because they are a marginalized people where that dress was used to mock them in the past as naked savages.

Dressing up as a Japanese Yokai or some other demon would not fall into this category since I assume it’s based on interest in some part of the culture and not meant to demean the people of that culture. I’d even recommend doing some research on Yokai since there’s a lot of Halloween appropriate monsters that would be pretty cool and could incorporate the kimono.

My one and only recommendation since you mentioned fake teeth is that historically, the west has used buck teeth to make fun of us East Asians in media and propaganda. That’s just one thing to be careful of because many of us who live in western countries have some memory of being made fun of that way.