[Athrun doesn't want to go. More than anything, he wishes he could stay right where he is. Him and Kaname, forever. She means the world to him at this point.

But he knows he has to. He has the power to make a difference. And it's because of his feelings for the girl standing behind him that he has to go. He has to keep her safe and living in a just world.

But when she says the words he's hoped to hear, he comes to a stop. He lets her approach and press against his back. He bows his head, letting his gaze fall to the ground.]

That's the first time you've said the words to me.

[He then pauses for a moment. Just two normal breaths. Then he turns around to face her.]

I love you, too.

[He reaches out with one finger to catch the tears that begin to flow from her eyes.]

And I will come back. If I didn't come back, I would never forgive myself. I love you too much to lose you.

[That's both his own love confession and his raison d'etre. He's going to preserve the land they live in so he doesn't lose her. He's determined to come back so that, likewise, he doesn't lose her.]