 If you liked NHK ni Youkoso! |  ...then you might like Oyasumi Punpun |
Both can be hilarious, dark, insightful, disturbing and lighthearted all at the same time. They're both slice of life about a naive character dealing with the world around him.
Both deal with individuals surrounded by people and situations that are rather psychologically twisted. Both contain very similar types of dark/morbid humor, and main characters with rather "lively" imaginations. The lead females (Aiko/Misaki) also have very similar issues and situations.
report Recommended by kasumisama
Both series can be pretty surreal as well as darky humourous at times in addition to focusing on characters who go through some pretty tough struggles in their lives.
report Recommended by Disapeared_Ghost
NHK ni Youkoso! is pretty much Oyasumi Punpun’s prototype. Both manga are dark, morbid and depressing, but sometimes (more so in NHK) insert some black comedy into the story. The artwork in both (more so in Oyasumi Punpun) are outstanding. If you’re looking for a light read, look somewhere else. But, if you want a dark and depressing read, NHK ni Youkoso! and Oyasumi Punpun await you.
report Recommended by SebCyrSC2000