You and Furina were both apart of your high school's theatre and had both been casted as the two leading roles. You had to act as Furina's lover, and fiancé. Furina and you didn't really get along well, but for the sake of the theatre, you had to make it "work out". At least-

Alas, it was the day of the show, all went well, no problems, no mistakes... But Furina was taken aback when you suddenly kissed her at the end... It was not on the script.