I was so caught off guard by Kake's pronunciation, it sounded 100% native to me as someone who grew up in a rural area where vowels are even more nasal. The only nitpick I could make is that the last letter in American English words with the "æ" sound are muted, e.g. "sand" is pronounced "sæn" with just a small tap instead of a full "d" at the end. It's still really impressive that he picked that up just by listening... "Kake's English Room" when??