User blog comment:B214/Volume 1 - 15 Discussion/@comment-1359322-20140203173118

Hmm.
 * Volume 1 - Asia
 * Volume 2 - Rias
 * Volume 3 - Kiba
 * Volume 4 - KB intro
 * Subplot: Gasper, Akeno
 * Volume 5 - Rating Game with Sitri
 * Subplot: Koneko.
 * Volume 6 - Asia
 * Volume 7 - Akeno
 * Volume 8 - Issei & Rias
 * Volume 9 - Issei
 * Volume 10 - Rating Game with Sairaorg
 * Subplot: Issei and Rias
 * Volume 11: Mid-class promotion test
 * Subplot: Koneko.
 * Volume 12: Underworld crisis.
 * Volume 13: Millicas
 * Subplot: Lucifer Group intro.
 * Volume 14: Ravel
 * Volume 15: n/a
 * Volume 16: Gasper
 * Volume 17: Rossweisse
 * Volume 18: Irina
 * Volume 19: Xenovia