Since the TL note at the end mentioned that the PT-BR uploads have the uncensored version of Ch.13, I looked out of curiosity.
There's literally nothing to see. The artist drew the outline of a toddler with vertical hatching for shading. The black rectangles aren't censoring a naked child...
Apparently the kanji for ブナ is normally written as 椈, so it's not just Osaka being Osaka.
On the other hand, deciding that a kanji made up of 木 and 無 must mean "not a tree"... It kinda makes sense, but that's not how kanji work, so that part is 100% Osaka being Osaka.
Japanese lesson of the day: セックスしないと出られない部屋 (sekkusu shinai to derarenai heya - a room you can't leave unless you have sex)
It's a staple of doujins that either want to set up an unlikely pairing without having to explain it or want to skip ahead a bit with a couple that just isn't at that point...