Because they'll live on in each other's hearts, right? As long the memory's there they never really leave. [ It's a sobering thought, considering all they've been through up until this point. And he realizes that Nageki will probably realize this too, so he scrambles mentally to think of something to say.

...and then he picks up the ring in a small cluster of candy. ] Huh? [ Are those... stars on it? Are those tiny gems? Hitori looks at the ring closely, puzzled. It looks too big for Nageki's finger, and too nice to be some free toy. But then why? ] What's this?