She grows quiet for a moment - and a little more awkward too. Mostly since she's so unsure what to say in the face of those words, since they come as that much of a surprise to her. Madoka didn't expect him to say any of this at all.

"But.."

Her voice trails off, and she briefly shakes her head.

"It's not like you'd be empty.. Ken-san, you have so many people you're close to, right? You have Wormmon, and you have your friends back home too.. You have so many people to have memories with. I'm.. I'm just one girl you met here on a strange train." And not even a particularly special girl on top of it. There's nothing she's really good at, nothing that makes her stand out from anyone else here - if there has to be any one person who has to be forgotten, Madoka knows it's for the best for it to be her.

"You wouldn't even realise you were missing anything. You'd just be happy."