I don't know much about Hirohito, or why he talks really weirdly in this (even when talking Japanese) -- as if his tongue's too big for his mouth, which is intriguing. Perhaps a type of etiquette? The film epitomizes character study. The directory himself claimed not to be interested with politics and what you'd be taught from, say, the History Channel, and so those subjects are partially ignored. Hirohito's in a bunker (as they all are), yet in the Imperial Palace, which is quite cozy, rather than claustrophobic hell. He reminisces not so much on the past, but on his and the future of Japan -- or lack of it.
It's a film that requires a lot of input from the viewer, introspection on this level is better suited to novels, but Sokurov's work will appeal to (and impress) certain audiences. Refraining from spoiling the plot -- or giving you a history lesson -- this is a film about what the man was or might of been feeling at the time (and throughout his life), his responsibilities, and his reflection on possible war crime accusations, which lead to awkward meetings to dictate peace terms with an American commander. Therefore, this is a film so many viewers will be either bored with, and perhaps bitterly disappointed that they weren't getting a historical romp or a heavy political showing.
Issei Ogata is the best Japanese actor I've seen -- especially in a role like this. What makes this role even more impressive in scale and to accomplish from Ogata's perspective is the fact that this wasn't screened in Japan due to right-wing extremists getting angry over the portrayal of Hirohito, yet Ogata and the other actors still had the guts to work with Russian director (and cinematographer) Sokurov to make this wonderful exploration of a 'human being' in an incredible situation. To think we as individuals, governments, uniting bodies and every country in the world fear atomic warfare -- this was the Emperor of a country watching his world burn before his eyes -- something even the Emperor, who was considered a deity in Japan -- a God amongst men -- couldn't control, or perhaps even understand; little of us can.