* Mina: She is Michael's neighbor and best friend. She is curious, observant, and a good friend to Michael.
* The boy next door: While his name isn't mentioned, he is a character who lives next door to Michael and Mina. He's described as being older and a bit of a bully.
It's important to note that the book focuses mainly on Michael's internal journey and his relationship with Skellig, so the other characters aren't as developed as they might be in other stories.