夏休みの『アイプリ合宿』では、サクラたちによる厳しい特訓が繰り広げられていた。一生懸命がんばるひまりたちを、じっと見ているつむぎ。アイプリバースでは、つむぎのアイプリブレスにエナジーが戻ってきていた。それを知ったひまりは、今すぐライブをしようと誘うが、つむぎはスペシャルなライブがしたいと言う。シークレットフレンズ∞を復活させるため、おとPプロデュースによるサマーフェス『アイプリ・ザ・サマー』が開かれることに！
During the summer vacation "AiPri Training Camp," Sakura and the others are conducting rigorous training. Tsumugi watches Himari and the others as they work hard. During the Aipri Birthday, energy is returning to Tsumugi's Aipri Brace. Upon learning this, Himari invites them to do a live performance right away, but Tsumugi says she wants to do a special live performance. In order to revive Secret Friends ∞, a summer festival "Aipri the Summer" is being held, produced by Oto-P!
Durante as férias de verão, "Acampamento de Treinamento AiPri", Sakura e as outras realizam um treinamento rigoroso. Tsumugi observa Himari e as outras enquanto elas se esforçam. Durante o Aipri Birthday, a energia amiga retorna ao Aipri Brace da Tsumugi. Ao saber disso, Himari a convida para uma live imediatamente, mas Tsumugi diz que quer fazer uma apresentação especial. Para reviver o Secret Friends∞, um festival de verão, "O Verão AiPri", está sendo realizado, produzido pela Oto-P!
