Completing the Kii Peninsula itinerary?

After some great advice here I have redone the itinerary for the second part of our trip... which is:
28th March arrive Wayakama stay one night
29th pick up hire car and drive to Yoshino - stay one night in monastery there (gorgeous!)
30th drive on to Shingu - stay 3 nights and drive up and down coast from there, also go to Karaatsu and walk to the waterfal and shrine.
2nd April drive to Hongu - stay two nights in little house there and visit the lovely area with some walks on the trail.
4th - need to be heading towards Wakayama BUT I DON'T KNOW WHERE TO STAY! PLEASE HELP.
We'll have been in the hills and little onsen towns for a while and will spend our final night in Wakayama on 5th (having taken back the hire car there) before flying out to Australia on 6th so I'd like somewhere lovely and not too touristy.
I hope someone has some suggestions please.

http://yuasajyo.jp/english/
Onsen in a castle, perhaps?

hmmm looks interesting Winter Visitor - have you been there/stayed there/seen it?

Not stayed there.
Had thought about it, but ended up going to Yuasa on a day trip from Wakayama.
Therefs a small old street district (where you can rent a machiya house - on air bnb), and a soy sauce brewery, which is worth an hour and which has great soy sauce ice cream.
The other place around there that I fancied- but didnft end up visiting- was Kainan. Lacquerware town - documentary avaioon NHK World.

Great news! many people have recommended that we try Kiri no Sato Takahara and I looked for it on hotel sites etc and it was always booked for our date. Finally found their own website and have been able to book a twin room for our last night before Wakayama and home. It looks divine and such a beautiful way to enjoy the end of a lovely trip!

Ooh!
Let us know what itfs like.
Happy travels!!