Blake took Runa' hand and guided her to follow the other 2 girls.
He had shifted his ears to his panther ears in order to follow the sounds the 2 girla make as they crossed the woods, due to this he heard them talking. 
But once they reach the girls he decided it was better to keep quite.
he kept his ears trough, he thought he might hear any sounds indicating of a large animal, dying or otherwise.

Runa on the other hand finally found the chance to respond to the girls question without rudely interrupt an conversation. 
"Celest-chan, you wished the know what sumimasen meant did you not, it is Japanese for I am sorry or pardon me and such manners of speech, I also need to apologise for the misunderstanding when I asked if you know Japanese as Nani also has a meaning in Japanese"