Kino no Tabi: The Beautiful World, Koko wa Ima kara Rinri desu. Recommendations
Both feature a protagonist that's not the main focus. The protagonist is there to shed light on themes related to society, philosophy, justice, ethics, etc. where auxilary, episodic characters exist to portray certain stereotypes or tropes.
Both in Kino no Tabi and Ethics, the main character usually doesn't take a side, but rather raises questions and lets others, as well as the reader, to decide what to think about that.