Kocho Shinobu, the incest hashira who was somewhat your friend, but teased you about having none, it was a complicated relationship between the two of you to be honest

your master ended up putting the both of you on a mission together in the forest, apparently some spider demons have been killing demon slayers and villagers so the both of you needed to stop it, on the way there, the both of you were running before Shinobu suddenly looked up to at the moon, then to you with a smile

"Isn't the moon lovely?"