Kazutaka Kodaka and Kotaro Uchikoshi join forces for the first time to deliver the ULTIMATE adventure game! 15 students are tasked with defending a school from grotesque monsters for 100 days. Can they make it to the end? And will they survive long enough to uncover the truth?

StoryTakumi Sumino is a totally average teenager living in the Tokyo Residential Complex, a place where every day is much like the last and nothing bad ever happens. All that changes when freakish monsters attack the town and start wreaking havoc. A strange creature calling himself Sirei appears and offers Takumi the power to protect those he holds dear... All he has to do is stab himself in the chest!

Extreme Despair-Filled EndingsTakumi's choices will decide his future, but there's no telling what kind of consequences these decisions might have...

When the invaders attack, it's up to you to protect the school in SRPG battles.

Use each student's unique Specialist Skills to turn the tide of battle in your favor!