itaiitai ni naru kara
itaiitai ni naru kara .
i t a i i t a i WORD_BOUNDARY n i WORD_BOUNDARY n a r ɯ WORD_BOUNDARY k a r a WORD_BOUNDARY
i t a i i t a i WORD_BOUNDARY n i WORD_BOUNDARY n a r u WORD_BOUNDARY k a r a WORD_BOUNDARY