@MsHearthWitch Pluto (recently adapted to an anime on Netflix) has some really good Sci-Fi thoughts and questions, though it may be more serious than you're looking for.
Blue Flag (published by Viz in America) is a story about a high school boy who develops a crush on a girl who has a crush on his friend, at least that's where it starts. It then goes on to look at some of the pressures modern day kids might face in high school (at least in Japan). High school drama, but feels grounded.
Generally, if you're looking to read manga, you can find fan transitions on MangaDex.