"Good night, Punpun"
Its basically about a blokes like, from ground schooler to a young adult. He and his family are portraied as these bird-things for the sake of immersion and i don't know anyone who didn't have this manga hit close to home at least once.
I recommend you consider maybe not look into it, and if you do make sure you're not already sad or depressed. The manga starts out with a mixture of happiness and disfunctional home, but the end after Punpun meets Aiko again is emotionally taxing to a degree unheard of. Not trying to sound edge, but I think the manga might have had an amplified effect on me simply because I found the main character and his experiences to be very similar to myself.
Not gonna lie, that manga ****** me up so bad I cried several times the next few days and had to go to the apothecary to get some eye drops.