Punpun and the members of his family are normal humans, but are depicted to the reader in the form of crudely drawn birds.

The manga explores themes such as depression, love, trauma, social isolation, death, and family.

When he initially planned the story, Asano wanted to chronicle Punpun's growth spanning ten years over seven volumes.

The manga grew to thirteen volumes because Asano wanted to focus on the art and because many characters developed their own side stories.

[4] When designing Punpun, Asano wanted to find a balance between making his male protagonist too handsome or too ugly and decided to let readers imagine his face.

[5] Asano originally planned to depict all the characters like Punpun's family, but his editor did not like the idea.

Outdoor backgrounds were created by taking photographs, converting them to black-and-white, and printing them so his assistants could draw outlines and objects on them.

When asked why he placed so much emphasis on the backgrounds, Asano said that it allows the drawings to have more impact, especially since characters like Punpun are lacking in dynamism.

[4] Written and illustrated by Inio Asano, Goodnight Punpun was first serialized in Shogakukan's Weekly Young Sunday from March 15, 2007,[7][8] until July 31, 2008, when the magazine ceased its publication.

[15] Some of these volumes have been sold as limited special editions with extras like: a phone strap, T-shirt, colored pencil set with figures, and lensless glasses.