I've seen Yuuna Himekawa listed with a single u a few times, but I've never seen Yuna Yamakawa listed as Yuuna.
Their twitter accounts confirm the different spellings...
View attachment 967733 twitter.com/yuna_yamakawa
View attachment 967734 twitter.com/himekawa_yuuna
It would be so confusing if they both went by "Yuna". Yuna Himekawa & Yuna Yamakawa lol.
I hope they work together one day!
I mis-read, and that is SO confusing. That will be an easy fix as I don't have many Yamakawa titles.