Arcana looks amazing and perfect. But no kids under 12. Am now looking at Aman (still a trek) since I'm suppose to be doing this for 1 day only between Kyoto and Tokyo. And also looking into a couple of high end ryokans (Yagyu No Sho, Beniya Mukayu) and sent an email to Hanafubuki.

Our itinerary is completely rushed
1 night in Tokyo
2 nights in Kyoto
1 night in Countryside
2 nights in Tokyo

A terrible itinerary. But Cherry Blossom season and dictated by lack of rooms in kyoto.