Question about the new OP

The new OP is just pure joy! It is so beautiful to see some of my favourite scenes and characters animated in real life, with so much detail! As someone who binge read the manga, I can't wait for the whole anime to come out.

That said, a couple of scenes from the OP, the one where Hina and Taiki are seemingly on a date, then Karaoke...!>looks like a dream sequence!<!. Did I miss it somewhere in the manga? or is this really something the anime director added. If so....that's just beautiful! and heartbreaking for all the Chono fans.