Fate/kaleid liner Prisma☆Illya 2wei!: Mahou Shoujo in Onsen Ryokou
Based on the manga by the same name by Hiroyama Hiroshi, itself a spin-off of the Fate/stay night erotic visual novel by Type-Moon.
Note: Bundled with the limited edition of the sixth Fate/Kaleid Liner Prisma Illya 3rei!! magical girl manga volume.
(Source: AniDB)