The Prototype Bracelet, otherwise known as the Iron or Platinum Bracelet, is a device that, upon saying the activation phrase "Awaken", allows the user to create a summoning field without the need of a supervising teacher. According to Yuuji Sakamoto, the bracelet can only be used by an idiot. Akihisa Yoshii, Yuuji Sakamoto and Hideyoshi Kinoshita acquired three of these bracelets during the orienteering competition, but the two bracelets worn by Yuuji and Hideyoshi exploded only moments after they activated them, making Akihisa the only person with one to use, being the only one who actually can use the bracelet.
The bracelet served a key role in repairing the Shoukanjuu Summoning System during Episode 8 of Season 1. In Episode 12 of Season 1, the bracelet Akihisa uses explodes because the device no longer considered him an idiot. In Episode 8 of Season 1, it is shown that the user of the bracelet is able to choose the subject of their summoning field, when Akihisa chose to fight Kouta Tsuchiya's Being under History instead of Health and Physical Education. Sometimes the summoning field of the bracelet is possibly additional space or range for wider-spanning Class Wars (but contains no subject or copies the subject of the summoning field beside it).
Light Novel VersionEdit
In comparison with the light novel version of the Iron/Platinum Braclet, there are several notable differences. The Iron/Platinum Bracelet was given to both Yoshii Akihisa and Sakomoto Yuuji as prize for winning the Summoning Tournament in Volume 2. Yuuji's bracelet gives him the ability to create a summoning field, but the subject selected is random. Akihisa's bracelet gives him the ability to summon two summoned beings with their points averaged among each other.
Likewise with the anime, the bracelet is defective to the point that people with better grades such as class A students, won't be able to use it. Yuuji's bracelet works, so long as the average score of the user is below the average, while Akihisa's bracelet only works for people with grades as low as his.