mmm it seems this EP has the Yamato "Musical Academy" chorus version but I don't find a scan of Side 2, the contents image is too small.
EDIT: found better scans that confirms it's the "Royal Knights" version. But if you do a comparison with worst scan of the label (Contents 01) it miss the second half of the last line after Isao Sasaki credit
Also check the Contents 03 image compared to the new I added. On the yellow field under the title there's a longer credit after Isao Sasaki.
So are there two edition with both version, or maybe Columbia correct the wrong credit after...
Aanison reports the Musical Academy chorus
It seems also there are two different edition of the
SCS-241
Anison report both:
http://anison.info/data/source/3483.html
http://anison.info/data/source/29780.html