This series is not even on hiatus. The author/artist got tired of this series and axe it/butchered it with dogshit ending. In free raw site you can see the comment in korean talking shit to the author
To be honest i've gotten my fair share of hentai or other weird shit that japanese have invented, hell you could say i'm a veteran in this particular field but after seeing this i must say how fucking naive i truly am....
i'm now convinced that Yotsuba is the first lolikano Fuutarou met 5 years ago (right after he realize he is being a third wheel to his friend in their trip).
If we look at chapter 66 (scramble eggs 6) page 8, you can see there Yotsuba recall about how Ichika playing with a boy (which i presume...