Aoi Sekai no Chuushin de

Episode 1
Images from the Onsen scene in Chapter 7 of the manga are seen in the episode preview for episode 2. The preview shows one of the manga scenes where Opal is seen bathing although in the actual scene in episode 2, the part in the girls side with Opal and Nel that was in the manga was taken out of the anime.

Episode 3
Part of Episode 2's Onsen scene is seen in a Flashback.