A break in the 5-7-5-7-7 meter?

Question

So I was reading about Waka poetry and then about the tanka meter, when I came across several poems by Ono no Komachi and Narihira. The ついにゆく poem from Narihira has 8 syllables rather than 7 in the last line and the first line in Komachi’s 花の色は has 6 syllables rather than the standard 5 right? I was wondering if this was allowed or is there a special rule where some sounds were combined or maybe I’m supposed to turn a blind eye and the meter is more of a ‘guideline’ rather than actual rules.

Answer 1

On some occasions it can't be helped, although whenever possible one avoids it.