Trinity Seven: The Seven Magicians 12

 is the twelfth volume of the Trinity Seven series written by Kenji Saitō and illustrated by Nao Akinari. The volume was released on August 8, 2015 by Fujimi Shobo in Japan.

Synopsis
Arata has vanished, and it's up to Trinity Seven to save him! Akasha Academy is the prime suspect--what is Anastasia hiding behind her knowing smile? The girls from Biblia and Liber Academies must form an unlikely alliance to ensure Arata's return. They say that 'the enemy of my enemy is my friend,' but can that new friendship survive...a Breakdown Phenomenon?!

Chapters

 * 49. United Front & Terminus Library
 * 50. Arc Light & Soul Gemini
 * 51. Ruin Walker & Rage Walls
 * 52. Lost Rune & Luxuria Girls
 * 53. Elemental Knight & Open Battle
 * 54. Unlimited World & Theophania

Characters

 * Yui Kurata
 * Arin Kannazuki
 * Master Biblia
 * Selina Sherlock
 * Lieselotte Sherlock
 * Hijiri Kasuga
 * Lugh
 * Arsha
 * Mira Yamana
 * Astral Trinity
 * Master Liber
 * Anastasia-L
 * Lilith Asami
 * Abyss Trinity

Flashback

 * Levi Kazama
 * Akio Fudo