a nan tte itte iru
a nan tte itte iru ?
a WORD_BOUNDARY n a n WORD_BOUNDARY t t e WORD_BOUNDARY i t t e WORD_BOUNDARY i r ɯ WORD_BOUNDARY
a WORD_BOUNDARY n a n WORD_BOUNDARY t t e WORD_BOUNDARY i t t e WORD_BOUNDARY i r u WORD_BOUNDARY