Where am I, Who am I, Why am I? [NEW LIFE]

[BL]
After being involved in a car accident together, Hajin is asked by Sihyeon to take care of Sihyeon's younger sister after his death. Hajin never expected that to mean he would wake up in the hospital in Sihyeon's body instead of his own. Even worse, Sihyeon was an infamous idol who would do anything for money, had multiple sponsors, and was apparently about to abandon the boy band he was a part of to sign a new contract with a larger agency. At first, Hajin believes the public’s negative

Rembrary, the deputy of God loved by all and the holy high priest.
When I woke up while fighting against the Demon King who invaded my world, I woke up as an underrated idol in Korea..!
Will he be able to safely adjust to the idol life and return to his original world?

Cayena, the Imperial Princess, was known as the most beautiful woman in the Empire. She was a woman who knew nothing but evil and luxury.
However, she was destined for ruin: she would be used as a chess piece by her younger brother to secure his throne and killed by her crazy husband.
“I’ll make you the Emperor.”
“… Sister, are you referring to me?”
“In exchange, give me freedom.”
She had to change things before she became that Cayena.

Who would've thought that rivals, the academic tyrant, Xu Sheng, and the top student, Zhao Zhan, would exchange bodies a few times and then start to like each other secretly! After many clueless situations the two became closer to each other, after they experience some funny stories and incidents, they finally understand their feelings for each other.