Despite all that's happened so far, I don't feel like Nozomi's complete change of personality and worldview is…
Well, there are lot of unbelievable things about this story that requires suspension of disbelief but it's still a good story. though this change came out of nowhere, it was important to Nozomi and everyone else's character development, and anyways it only lasts for an episode or so.
It feels extra strange because I was born 2001 myself
I was born in 2000 myself so I get how you feel. The age gap made feel me feel weird too but this couple kinda works imo??? They look good together and neither party takes advantage of each other, they just help each other grow.
I'd suggest Someday or One Day. Although Someday or One Day is a bit more complex when it comes to the time traveling…
I love Someday or One Day! It was one of the dramas that got me into Asian TV shows. SDOD and Todome no Kiss both also have the distinction of having amazing soundtracks that I listen to on repeat.
4 
character development, and anyways it only lasts for an episode or so.