The Great Birthday Surprise

The Great Birthday Surprise: The Target is Guren Ichinose (華麗なる誕生日（バースデー）サプライズ ～ターゲットは一瀬グレン～) was an event in the Seraph of the End: Bloody Blades game that ran from August 23, 2016 to the game's closure on September 29, 2016.

During the event period, players were able to run the event quest in order to collect the event-exclusive item, Guren's Treasured Photo (グレンの秘蔵写真). Collecting this would allow the players to draw from the Event Gacha at the summoning page.

Players also stood a chance to get a copy of a random character from the Event Gacha after successfully clearing the event stage.

Event Gacha
During this event, the Event Gacha pool consisted of all characters that were obtainable only through the Event Gacha in all past item events, including SSR and SR rarity cards.

As with all past Event Gacha instances, a single draw requires 100 event items.

The characters that were obtainable during this period were:
 * 0176 Mikaela Hyakuya
 * 0177 Shinoa Hīragi
 * 0179 Mitsuba Sangū
 * 0207 Shinya Hīragi
 * 0208 Shinya Hīragi

Event Quest
Cards that were obtainable from drops during the event period were:
 * 0064 Shinya Hīragi (SR)
 * 0224 Mitsuba Sangū (Snow Christmas Night SSR)
 * 0228 Yūichirō Hyakuya (New Year Uproar SSR)
 * 0239 Mito Jūjō (Blow The New Year Holiday Mood Away SSR)
 * 0257 Chess Belle (Sweet Sweet Valentine SSR)
 * 0297 Guren Ichinose (Guren Squad Gathering SSR)
 * 0306 Shigure Yukimi (Guren Ichinose's Birthday Mission SSR)
 * 0321 Shihō Kimizuki (One-Time Special Live! SSR)
 * 0330 Mitsuba Sangū (Blow Away the Summer Heat! SSR)