Nijo on first impressions is a heavily perfumed sandalwood stick, on first light I get a strong floral top note of jasmine and wisteria, with a mid note of fruit (maybe apricot or green grapes?) and a slight hint of vanilla amber and talcum.
Shirakawa is a stick with a rich, full bodied scent of vanilla and amber, with a hint of floral and dry sandalwood in the background. There is also a tiny base note of talc hiding out in the burn.
Genroku is quite diffrent from the first two, in that it has no overt perfumes or oils that I can tell, and insteads seems to be composed of a blend of aloeswood, with a top note of cambodian or vietnamese aloeswood and a base note of sweet agarwood.
Muromachi seemed to have a sweet spiced scent to it, with a blend of agar and dry sandal at the base.
Tenpyo is straight vietnamese agarwood, with the rich resiny aroma associated with such.