"...What's, going on. Halter, what kind of joke is this!!" Naoto and Marie are betrayed by none other than Vainney Halter.The gang is visiting the crime capital of the world, Shangri La Grid. But what awaits them there is not only an unexpected betrayal and conspiracies, but a new Initial-Y...The fourth installment of the overhaul fantasy by Yuu Kamiya x Tsubaki Himana x Sino!