Here's the subtitled version, along with approximate translations:
Chiaki: Ich warte in der Zukunft. (I'll be waiting in the future.)
Matoko: Ich komme sofort. Ich laufe dahin! (I'll come immediately. I'm on my way.)
And the dubbed version:
Chiaki: Ich warte in der Zukuft. (I'll be waiting in the future.)
Matoko: Ich komme bestimmt. Ich liebe Dich! (I'll be there. I love you!)
Chiaki: Ich Dich auch. (I love you too.)
Gah. What on earth possessed them to add that to the end? I might not know any Japanese, but I do know that Chiaki did not say anything at the point where the German dub added the final line. This sort of thing is almost insulting, as if we're are too dumb to get the idea without it being laid out on a plate for us.
Mind you, maybe it's a German thing. Jean-Pierre Jeunet's last movie, correctly called A Very Long Engagement, hit the German cinemas as Mathilde—A Big Love. So I guess the movie got off lightly. At least it didn't end up being called A Love That Transcends Time or something similarly crass.