You don’t need a Japanese cousin named Yuna. You just need and an overnight setting. Try these variations:
But that still doesn't form a natural Japanese sentence. Could you mean something like: shinseki no ko to o tomari da kara eng better
So the intended story is clear: The author is staying with a young relative who speaks English. Through exposure and necessity, their own English skills have improved. You don’t need a Japanese cousin named Yuna
have dedicated threads where viewers discuss the best versions to watch. Avoid Parodies: shinseki no ko to o tomari da kara eng better