I have heard the following sentence in an audio file of a dialogue in the Japanese language teaching book Genki (vol 1):
はがきは イギリスまでいくらですか？ (= How much is a postcard to the UK? )
There is a clear N sound in the syllable が of はがき and I hardly hear any G. It seems to me that the speaker is pronouncing が as [na] or [ŋa] instead of [ga] (IPA syntax). Is that an accent? If so, from where?