Huh, ther're bouncing their words off the walls, like echolocation. The word balloons also have an echo effect. Nice touch of detail.
grip...
Rain Shelter for the Vampire Sisters
Huh...? She won't let... go?Hey—you two!? So strong even when you're asleep......oh well... might as well rest for a bit until they loosen up their grip...Here, Flan, Remilia, we've reached your bed...*Conversation in ultrasound
Flan...
I can hear you, onee-shama.
Alright then... even Sakuya-san's already fallen asleep...