This dlc required orginal game,you can download this here
Copy folder “Archive” into the root folder of the game.
After completing the main game, start a new game, choose a name and select the after story you would like to play.
Title: Fureraba ~Friend to Lover~ Mini Fandisk
Original title: フレラバ 〜Friend to Lover〜 ミニファンディスク
Length: Short (2 – 10 hours)
Year: Japan 2014-08-15, English Version 2019-02-15