Well I didn't know Hong Kong drinks are getting popular in Japan.

It's not actually entirely coffee: it's a mixture of coffee and tea in condensed milk. It's called Yuan Yang in Mandarin or Yun Yeung in Cantonese. (鸳鸯/鴛鴦 in hanzi)

I guess the Japanese really like their light novels.

I tried using the Japanese IME to type from the suggested Japanese pronunciation of the drink えんおうちゃ and it pretty much asked me "Seriously?"

I could write the name in kanji but I was like "fuck that" since it's the same as the Traditional Chinese name.

Turns out the term is recognised and already exists, but it's very obscure since it is a HK drink anyway.

I guess it's similar to how Chrome doesn't think the word "halation" exists unless you specifically teach it the word.