After the events of Alternative, Shirogane Takeru return to his original universe of the Extra timeline where Earth has not been invaded by BETA. There, he was left without his memories of the time he spend in the Alternative timeline. However, deep down, his subconscious would, from time to time, feel emotions that he wouldn’t normally feel as though his soul itself remembered for him. Not to worry though cause he’s back in top shape and is continuing to live his life as a high school student.