Since Japanese has pitch-accent rather than stress-accent none of these various spellings/boldings are likely to capture the actual native pronunciation, which is part of the source of confusion. I believe that the high front vowel is always tense /i/ and so "neato" is probably closer to it. As the accent is lexical and not represented by the spelling, we would need a native Japanese speaker to say whether Nitto has an accent or not.

/notscrod
/too many years as fricking linguist even though I don't really know phonology