Daten no Inugami: SLASHDØG - High School DxD Universe

Second-year high school student Tobio Ikuse is left behind when a severe fever forces him to miss his class trip aboard a luxury liner. Four days later, devastating news reaches him: every teacher and second-year student on that voyage has vanished without a trace. Months pass as Tobio slowly struggles to cope with the sudden loss of his friends, until an unexpected encounter shatters his fragile recovery. While chasing after Sasaki, one of his missing classmates, Tobio catches up to him only to find his friend standing beside a monstrous lizard-like creature. The beast attacks without warning, cornering Tobio until another survivor of the vanished ship, Natsume Minagawa, intervenes to save him. Before disappearing, Natsume presses a mysterious egg into his hands. That same night, Tobio is ambushed again, this time by two hostile individuals commanding monsters of their own. Amid the chaos, a puppy emerges directly from his shadow, fiercely driving back the attackers. Following the battle, Natsume reappears and finally decides to lead Tobio to a hidden refuge, drawing him deeper into the dangerous mystery surrounding the lost voyage.