Manga (and some manhwa) I think you should read. Most of them are pretty short but all of them are completed. I will add more as time goes on. Clicking on the image will lead to its respective Mangaupdates page.
Synopsis: Jobless 27 y/o main character meets a guy who gives him an experimental pill that can give him an appearance of a highschooler. MC has to go to highschool as part of the experiment.
Opinion: I can't believe I have not read this manga before. It has everything, good art, loveable characters, great story, and honestly I should stop rambling you should definitely read this!!!
Kuma Rates: 9/10
Synopsis: It’s about Nakamura trying to befriend his massive crush while being shy af and clumsy.
Opinion: I honestly love the 80s style it’s going for, and the characters in this story are really likeable! Definitely recommend even if you are not into shounen-ai.
Kuma Rates: 7.5/10
Synopsis: A tragic rom-com where there is a disease that determines the amount of heartbeats you have when you are born. One such victim wants to experience things that would make her heart beat faster to enjoy the last moments of her life. Another one helps her with that. Romance happens. Opinion: This oneshot has better romance than most serialized manga, and will leave you in a sobbing mess.
Kuma Rates: 8/10
Koe no Katachi
Synopsis: The protagonist bullied a deaf classmate in his childhood, so he tries to repent for that during his highschool years. Romance happens. Opinion: Even if you have already watched the movie, you should still read the manga since it fleshes out the side characters more and feels like a complete story.
Kuma Rates: 8.5/10