Sounds like a real departure for Koreeda. But his films always had some fantastic elements to them. And this one obviously also revolves about death - the right to kill. 
Actually what piqued my interst the most was your mention of some joyous renaissance music. I'm currently constantly listening to Monteverdi's L'orfeo opera which I bought a couple of days ago. And I just love the "dance" music from the renaissance. 

Could you say more about the music used in Hana, Howard?