Pixiv: https://www.pixiv.net/member_illust.php?mode=medium&illust_id=69489971

Character is No. 23, Nimi Shea.
Go to this album for more of this character: https://e-hentai.org/g/1263404/24f1edaa45/

The other magical student that shows up at the end is No.51, Nanai.

Updated with cover page.

Characters appearing in this doujin:
Shea: https://e-hentai.org/g/1263404/24f1edaa45/
Nanai: https://e-hentai.org/g/1263405/61e2de1924/