Summer Magic (夏の魔法 Natsu no Mahō) is the twenty-fourth chapter of the Kozue Amano manga Amanchu!.
It was originally published in Monthly Comic Blade on May 30th, 2011, and was later republished in Amanchu! Volume 4 on March 10th, 2012. In the original Monthly Comic Blade serialization, Chapter 24 was released as Chapter 23, but the chapter order was altered for the volume releases.
Hikari Kohinata and Futaba Ooki take Futaba's friends Chizuru Himeno and Akane Mizunashi to Kino Kohinata's beach cafe, Amanchu-ya where they meet up with Mato Katori. Because it will be Chizuru and Akane's first ever dive, Mato briefs them on the basics of diving while Futaba and Hikari prepare the equipment. While they browse through the guide books in the cafe, Chizuru notices Futaba and Hikari laughing and having fun out on the beach, and mentions to Akane that she's realized how much Futaba has changed - she used to be hesitant and indecisive and couldn't do things independently but now she's much more confident.
After reviewing all the basics and filling in the necessary forms, the group put on their wetsuits and go into the ocean. They start by some snorkeling, and Akane and Chizuru are both awed by how many fish they can see. While getting ready to go underwater diving, Chizuru asks Hikari why she calls Futaba "Teko", and she explains it's because of her small eyebrows looking like Tenten diacritics. Chizuru doesn't really understand, and thinks it's a stupid nickname, but doesn't say so.
The group puts on their regulators and start to dive while holding onto the guide rope. Distracted by her feelings of jealousy towards Hikari, Chizuru forgets all the diving basics she was taught and suddenly has intense ear pain because she hasn't regulated her ear pressure. She starts to panic from both the pain and from watching the rest of the group swimming away, having not noticed she's in trouble. Suddenly Hikari appears and, using an underwater writing slate, reminds Chizuru to clear her ears. She does so, and the pain stops. She panics again, seeing how far away the rest of the group are, so Hikari takes her hand and helps her swim towards the others. They swim to a deeper part of the ocean and Chizuru is awed by how pretty it is looking up at the surface.
Much later, Hikari and Futaba take Chizuru and Akane back to the train station, where they chat about how beautiful it was underwater. Chizuru shatters the mood momentarily by mentioning how she'd felt in pain and abandoned by the group, but follows it by thanking Hikari profusely for noticing and helping her by reminding her to clear her ears and catch up with the others. Hikari is relieved because she thought that Chizuru hated her, and Chizuru explains that she had tried to hate her because she was jealous but she couldn't stay mad at her because she realized how nice Hikari is and that hating Hikari wouldn't help deal with her complicated feelings either.
Chizuru and Akane head off towards the train, and Hikari shouts out to them, asking them to promise they'll come back and visit again. Chizuru responds that they'll come back "whether they like it or not" and that they'll leave Futaba in her care until they come back next time.