"10,000 degrees in peace square. I know it. The temperature of the sun in Peace Square."
Elle says this in the opening of the film as we see images from Peace Square, a memorial to the memories of the first nuclear bomb victims. The heat is an allusion to the love between her and Lui having burned hot but also dying out.
ELLE: We'll probably die without ever seeing each other again.
LUI: Yes, probably. Unless, perhaps, one day...a war...
ELLE: Yes. A war.
Elle and Lui are seen speaking about their relationship having come to an end. They are saying here quite plainly that they will never see one another again unless a war happens where their countries must fight agains one another.
"I'll forget you! I'm forgetting you already! Look how I'm forgetting you! Look at me!"
Elle screams this at Lui. She is clearly moved by her feelings for Lui, which she does not want to show to him as she does not want to give him the satisfaction of knowing the effect he's had upon her. Even still she cannot contain this and erupts the words upon him.
