Naofumi hates the king, and with good reason. With his daughter Malty, the king set Naofumi up as a criminal with the charge of rape and spread the word all over his kingdom. However, given his genuine display of stupidity in believing the claims that Naofumi could brainwash people, it's also likely he just believed Malty's claims. Ultimately, the king hates the Hero of the Shield, and that just unfortunately happened to be Naofumi. When the Queen cleared Naofumi's name and allowed him to punish the king, Naofumi immediately asked for the death penalty, but was talked down to renaming the king to "Trash" and stripping him of all his rights to the throne. After the death of the Witch, Trash seems to no longer be mentally aware of the world.