Nanako-san's Daily Life - Vol. 1 Ch. 17.5 - Volume One Extras

[MangaDex]

 

[Esper]

Labeled as "adult only" makes some sense because this is the Nanako series where you get to see her butthole a few times.

 

[raze2012]

ahh the manga that reminds me that I clearly went to the wrong middle school.

Yeah, censorship is pretty weird. I think the other issue comes down to magazine publisher choice. Some are fine as long as the rating is good, others will be like Nintendo family friendly and not take any risks.