As with many entries in the Naughty America series, "Vol 78" focuses on office-based adult scenarios. The plot, if you can call it that, revolves around various interactions between colleagues that inevitably lead to sexual encounters. While the storyline is somewhat predictable, it's not the focus; the real draw is the explicit content.
The "2021 x upd" notation suggests that there has been an update or a new release in 2021. Without specific details on what this update entails, I can infer that it likely involves new content, possibly with updated themes, actors, or storylines. naughty office vol 78 naughty america 2021 x upd