Everlasting

"In a world where you cannot find happiness, does it even have meaning to continue?"In the ancient city secretly invaded by the monstrous 'Nue', Kawase Ryouichi, there exists an ability user group battling against the 'Nue', known as the 'Abandoned City Organization'.Among them, hailed as the strongest ability user, the second-ranked Akihime, has a cherished best friend... a girl named Mei.Praying for her happiness, she fights secretly alone. But Mei is an assassin sent to Akihime's side from childhood with the sole purpose of killing Akihime.