Hiro is a sweetheart who rushes to help people (ghosts mainly) without properly thinking through the implications of his actions. Maddox is a grumpy reluctant cat dad who is hella suspicious of Hiro. The ghosts themselves are absolute characters (and lemme tell you now, they only get funnier the further into the series you get!).  I love that we see a mis-conception trope instead of just  miscommunication as the characters make assumptions about each other before finally things come out. 
10/10 loved it and recommend you keep reading because ngl, the ghost banter and the sass gets SO much better!