Real, Kokou no Hito Recommendations
Both depict how social misfits (The Climber - an introvert who distances himself from others due to his own personality and unfortunate past; REAL - people who need to rediscover their place in society due to their disability) who find solace in the passion of sports, to escape from the crushing loneliness as a result of their respective circumstances. They both showcase incredible depth in storytelling and breathtaking artwork. The Climber and REAL are mature, soul-searching dramas that are certain to grip the reader in more ways than one.
Sports mangas that go way beyond that category, these both have some of the best artwork that can be found in manga ( or make that anywhere ) and both are mature, intense and the characters have difficulties that they have to overcome emotionally and develop. These are both among the best mangas out there on a wide variety of levels. These are manga that will definitely make you feel and think.
Both focus on the development of their characters leaving the sport in the background (mainly Real), and both approach their respective sports in a didactic way.
If any of this manga piqued your interested thanks to their realistic perspective on sports and human emotion you should definitely check the other. The two books also share a lot of tragedy.
At some point, both protagonists go through a depressive phase or a phase where they're looking for a reason to keep living/practicing sports. They also had issues in their past.