Fate/kaleid liner プリズマ☆イリヤ ツヴァイ! 魔法少女in温泉旅行
Fate/kaleid liner Prisma☆Illya 2wei!: Mahou Shoujo in Onsen Ryokou
OVA PG-13 HD Sub 1
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)