A fog-draped morning, Tsuna is called out to Nami Junior High (?) by a mysterious phone call. On the way there, he runs into Yamamoto, Ryohei, and Gokudera. It turns out that Gokudera had come looking for Tsuna, but Yamamoto and Ryohei had been called out by the same kind of mysterious phone call. Is this one of the Arcobaleno’s tests…? They await suspiciously, and before them, Mammon—or Viper—of the Arcobaleno appears. Mammon says he has taken Kyoko hostage. Regardless of Tsuna and the others’ distraught faces, Mammom coldly kicks off a new mystery-solving game.
C'est maintenant le test d'adaptation de Mammon qui est proposé à Tsuna, Ryohei et Yamamoto. Ils doivent résoudre toute sortes d'énigmes et venir à bout des puissantes illusions de l'Arcobaleno Viper qui se fait appeler Mammon.
Tsuna, Yamamoto, Gokudera e Ryohei si dirigono verso la scuola e incontrano Mammon, che gli mostra di aver rapito Kyoko e che la libererà solo se supereranno la prova degli Arcobaleno.
第三项考验由阿纲、山本和了平参加，负责的考官则是玛门。然而玛门不只抓了京子当人质，手中还拥有某种似曾相识的东西，那就是在十年后的世界成为战斗主力的匣兵器。
Viper reúne a los guardines, y comienza su prueba teniendo como rehén a kyoko. La prueba consiste en responder acertijos para así poder salvar a kyoko y lograr su sello de arcobaleno. Mientras que Viper crea ilusiones y hace pruebas con las armas caja que le entrengo Verde. Finalmente Yamamoto, Ryohei y tsuna logran pasar la prueba combatiendo en equipo.
