this is a great ryokan. everything you expect. but note it's quite far from kumamoto. Luckily we hired a car and drove from Fukuoka (as we were doing road trip around kyushu island) . but if we didn't drive a car, not sure how we would get here.
The Onsen is a must try. We stayed in April 2018 and it was about 10 degrees celsius outdoor and the onsen was perfect for the weather. There was outdoor private onsen which you can pay 1200 yen for 50 minutes use. or the public one which was very nice.
We recommend guests to eat in the ryokan for breakfast and dinner, as i am not sure where else you would eat as the location is very secluded.
Also check out was at 10am, so we booked 2 nights instead in order to check out late, maybe around 2pm.
Also bring your own pillow as they give you pillow stuffed with beads inside, which wasn't very comfortable to sleep on. i woke up about 3 times during the night because of the pillow which we are not used to. The hotel should allow guests to choose conventional pillow and the bead filled japanese pillow. Overall, i won't stay here again, but it was great place to try the ryokan experience. the Onsen and the food was worth it.