Prince-Turned-Idol & the Knight Who Stans Him 2: United at Last

"Should we decide on a day for the two of us to 'do it'?"

Takao, a former knight who has been reincarnated many times, and Ko, a former prince, finally confessed their feelings, which had spanned their past lives, and became lovers!
However, in their current lives, they also share the relationship of manager and idol, and they have yet to go beyond kissing.
While Ko spends fulfilling days being cherished by Takao, he is troubled, wanting to take the next step as lovers. He wants to be seen as a proper adult...
On his twentieth birthday, Ko confides the feelings he has been harboring. In response, Takao suggests they promise a day for the two of them to "do it"...!?

Source: Amazon, Translated