[Ruca could probably explain that he ran away from the army the first moment he and his friend got a chance, but considering that it makes him a deserter then maybe it's better not to mention that for now. Especially to someone who wanted to join army on his own accord.]

So you're a soldier? I can see why this place would be different than what you're used to.

[He smiles ever so slightly.]

Thank you, Childe. I promise it wasn't all bad. My friend were with me... and I may not like fighting, but I can still do it.

[As for staying here.]

...It is a nice place to stay but... I miss my family sometimes.

[He gets homesick easily.]