Why are this dating sim's characters into an NPC!?

After being hit by a truck, Tomoya Miyuki wakes up in the world of "Dokimelo High School," a popular dating simulation game. He is the female main character's best friend, who helps her end up with one of the potential matches in the story.
Just when Tomoya's made up his mind to enjoy the kind of high school experience he never had in his previous life, he realizes he's attracted an unusual amount of attention from one of the romance options... the ever-popular Yukito Sakakibara. To top it off, Yukito ends up helping Tomoya remove a capsule item stuck inside him...!
A romantic comedy between a handsome, mysterious otome game character and an average Joe who was supposedly reincarnated as an NPC!