In the fansubbing world, footnotes are kinda reviled, such as the infamous Death Note "Just as keikaku. (Keikaku means plan)" translation. But for things that

In the fansubbing world, footnotes are kinda reviled, such as the infamous Death Note "Just as keikaku. (Keikaku means plan)" translation. But for things that make cultural references, like Gintama, even someone who knows the language itself won't know every cultural reference, so they can be useful.