The general feel of the shows is very similar, firstly. It's centered around a lot of growth, and explores friendships and relationships.
The leads in both the shows have dreams that they are chasing, and they are trying to navigate their relationship along with them.
SPOILER:
The largest similarity, however, is in their endings. They separate because their timings were wrong, and they were at stages in their lives, where it was just not possible to be together, if they also wanted to follow their own paths. And so they separate. But both endings are ambiguous, and give us hope, that one day, when the time is right, they might reunite.
And I truly appreciate these endings. They're very realistic.