Oz no Mahou Tsukai (1986) - 01 [ARR].mp4

??? softsub or hardsub??

It is mp4. Hardsub!

http://www.videoconverterfactory.com/tips/add-subtitles-to-mp4.html

@Otakuopa, As one who has done encodes, an MP4 container is also capable of containing softsubs if you have the correct tools, Those tools are simply not as well known as the equivalent tools for mkv files.