@ShionSinX
Yes. Ichicka was the second Quint to meet and spend time with Fuutaro in Kyoto 5 years ago.
Read Chapter 85, page 13 https://mangadex.org/chapter/613160/14 for the flashback... Yotsuba comes back to the hotel where all her sisters are and tells them she met a boy and spent the day with him and the boy is still here in the banquet hall. And then you see Ichika walking afterwards and find Fuutaro in the banquet hall. He has no idea that it's Ichika but it is implied so far that he spends the rest of the evening with Ichika talking and playing cards (sevens) until late/early morning.
And then the flashback continues to Ichika seeing Fuu at the school festival with the blond wig and it, to me, shows that's the moment Ichika realized that Fuu was the boy in Kyoto. (confirmed because if you look at page 4 and Nino saying she noticed Ichika had taken an interest in Fuu-kun since day one, she tries to deny it but she says that "it wasn't until that night that I remembered (Festival night seeing Fuu with the wig).
Then Ichicka's flashback of those memories end with her saying with within all the lies she told, the the brief moment she spent with Fuu that evening 5 years ago was not a lie and realized the first time she fell in love with him.