The Oxford English Dictionary has added several Japanese words to it, such as mangaka and isekai. You can check out the entire list of newly-added words, including non-Japanese ones, via the official OED website.
Some of the words are ones that normal people (here meaning those who have an entry-level knowledge of Japanese pop culture and media) use on the daily. For example, there are lots of Japanese or Asian restaurants that offer katsu and such. Below is the list of new Japanese and anime-related words in the OED, as well as links to their definitions. As a reminder, some words will require an OED subscription to see the definition.
According to the OED, isekai is “a Japanese genre of science or fantasy fiction featuring a protagonist who is transported to or reincarnated in a different, strange, or unfamiliar world; frequently used as a modifier.” Ever since the emergence of the Truck-kun meme in 2015, English anime fans have used “isekai” as a verb or a genre descriptor. With more and more isekai content these days, it stands to reason that it would start entering the public “normie” consciousness.
You can check out the entire list of new words in the OED via the official website.
