[Anime] A Certain Scientific Railgun S

Is this arc from the railgun manga or anime original? I"m getting the feeling its anime original written by Kamachi. I really should read the railgun manga.

As for the Endymion movie: the visuals of academy city were great. If you have followed Index everything will be clear. Don't watch if you are new to Index. The story wasn't incredible, just felt like a short LN.

Transforming robot, railgun in space. Great battles.

Footnote of worth: Mikoto can breathe in the very thin air in the upper atmosphere. Oxygen is paramagnetic so she can control it relatively easily. She does something similar to breathe underwater and make herself fly in the Liberal Arts City story.

I enjoyed the final episode despite the corny-ness of it, the esper battle was pretty good but there wasnt enough use of Mikoto's Railgun.