異世界から生還したら、クラスメートに幼馴染を寝取られてたので俺は彼女の記憶をデリートした

Kirishima Kaname, a middle-aged man who has returned from the other world of Dragalea, suddenly finds his childhood friend and girlfriend, Sendō Kaori being cuckolded by the handsome Yamazaki.

Kaname, who has been through thick and thin, dreaming of a reunion with Kaori, despairs and erases all memories and reminders about her.

Before going to the other world, Kaname was just an introvert, but his position changes when Hanayama, an outgoing person who wonders what he was doing while he was missing, gets involved.

The false-smelling tale of adventure in another world was well received, and his classmates began to gather under Kaname, making him very popular. Among them was the school’s most beautiful girl, Kagetsu Yoshino, who was an unparalleled fan of otherworldly fantasy novels.

Kaori, on the other hand, feels remorse and tries to apologize to Kaname, but Kaname treats her like a stalker for having erased his memories of her, and she becomes emotionally ill.