If you mean when Collin and Robin sing the "Love, Love, Love" song, then yes, most likely it's the last scene. You can check the memorabilia. If there is no "???", then that means you have unlocked them all. If I'm not wrong, the scene you are talking about is in the Date section, titled "Our Song". But if it's not and you still have "???" all over the place, then I have no other choice but to tell you to play the route all over again XD Or just unlock the memorabilia with "show memo" cheat code.