I like this even though I don’t read manga. From time to time you just stumble upon a comment that explains that in manga … actually … and it was …. And it all makes a lot of sense! It creates out-of-band immersion unavailable to most western stories, which often just hand-wave shallow stereotypical motivations and world mechanics.
It's especially fun when it's the same tone as other instructional works, but the thing being taught is totally fictional. Delicious in Dungeon by Ryoko Kui is a phenomenal manga that combines a deep love of classic tabletop gaming, goofy humor, and detailed cooking advice but for cooking monsters.
And on the opposite end of the spectrum, because that level of instruction comes with the genre, it can be amazing for a creator to purposefully avoid that. Taiyo Matsumoto is a weird vibey almost abstract artist, and when he took on the classic sports manga structure in Ping Pong he intentionally explains nothing about how Ping Pong works lets the whole story play out via the main characters repressed feelings.
