It's transcribed into Japanese as /ng/ (or /ngu/ at the end of words
) - at least for English, but not for Chinese and Korean. It's one pronunciation "error" the Japanese make that I've never really bothered correcting in lessons, as it doesn't impact their English much, and they might even have positive reinforcement of that pronunciation from some people. (like my coworker from Manchester who I'm pretty sure says the /g/)Where it becomes a problem is actually for /n/ and /m/ at the end of words in English, as the Japanese coda-/n/ (ん) is underspecified for POA and actually sounds like [ɴ] or [ŋ] a lot of the time. It becomes [n] before other coronals and [m] before bilabials, but can also be [m] at the end of utterances, if the person closes their mouth after speaking for example, and before vowels it sounds downright weird, like a nasalization plus glide. And if they take this as an L2 error into English it can be difficult to understand.