Nero is Neru's baby brother and the favorite of their tutors.  His dream is to be a famous monster hunter someday, almost like a superhero, and puts a lot of effort into his studying and physical training.  He's an "annoying little brother" type, actively going out of his way to pester his sister.  He can be a little vain and full of himself, since he's completely aware that he's the family favorite and probably the most talented monster hunter in training, despite just being a 13 year old kid.

*This character makes a physical appearance and has lines in EPISODE 1!