 If you liked
Fujiyama-san wa Shishunki
|
 ...then you might like
Ase to Sekken
|
At a glance, it looks like the series is just some fanservice-ecchi kind but it actually a pretty wholesome romance with a great interaction/development between the mc and fmc.
Both start the series where the main characters are in a relationship pretty early in the series.
Ase to Sekken development is focused more on the trauma of fmc while Fujiyama-san wa Shishunki is more about seeing the main characters grow up naturally.