1x13 - Amanchu!

An unaired episode bundled with the Blu-ray volume 7 // Futaba's friends from her old school, Chizuru and Akane, come to Izu to pay her a visit. As Hikari and Kino give them a tour of the town, Chizuru starts to feel jealous over how close Futaba is with Hikari. The next day, Chizuru and Akane are invited to take part in a beginner's diving course. In her eagerness to keep up with Futaba, Chizuru experiences severe pain from forgetting to equalize her ears. Thankfully, she is helped out by Hikari, who leads her the rest of the way and shows her the beauty of the ocean. Afterwards, Chizuru gives Hikari her gratitude and apologises for her attitude towards her before returning home with Akane, promising to come again someday.