[ Conflicting words for Shu to hear, but he'll take it as something more positive than negative. It's cute that Sayo wants to protect his brother from any looming dangers, but... he's just a kid? ]

... you're a very thoughtful brother. If he's here, we should find him so you can be together again. I'm sure he misses you very much.

[ But Shu doesn't know anything about his circumstances, or anyone's for that matter. Still, he won't let Sayo go anywhere without backup. ]

Besides. If something goes wrong, you may need some assistance.

[ He has no weapon, but his fists will do. ]