Many original files are released in 720p. A "fix" often refers to an AI-upscaled version that sharpens the image for modern 4K or 1080p monitors.
: The term "hent fix" could imply a search for a fix or patch, possibly related to hentai content, which is a specific genre of adult anime or manga. This could also refer to fixing a subtitle or translation issue, but without more context, it's challenging to provide a precise answer. shinseki no ko to o tomari dakara 1080p hent fix
The gold standard; it plays almost anything. Many original files are released in 720p