wakaranai to ikenai kara
wakaranai to ikenai kara .
w a k a r a n a i WORD_BOUNDARY t o WORD_BOUNDARY i k e n a i WORD_BOUNDARY k a r a WORD_BOUNDARY
w a k a r a n a i WORD_BOUNDARY t o WORD_BOUNDARY i k e n a i WORD_BOUNDARY k a r a WORD_BOUNDARY