Haramasa gives you the impression that they are a kappo restaurant that serves trendy "Tokyo-style" cuisine, which is clearly different from the traditional kaiseki cuisine of Kyoto.
You could even say that Haramasa resembles Kadowaki because they both serve clay pot rice with truffles. However, I personally prefer Haramasa over Kadowaki.
(They were one of the few Kaiseki restaurants in Tokyo that I liked the most. But the prices for their full-course meals went up substantially after they relocated, and their cost performance deteriorated, so I haven't been going there these days.)
Well, nevertheless, there is no change to my assessment that they are an establishment for which there is no harm in trying once as a Tokyo-style kaiseki restaurant.
If you are going out of your way to get there, I'd like you to definitely enjoy their sashimi in season, to be savored with shoyu mixed with the innards of a monkfish; "gout" somen noodles with dried mullet roe and caviar; and "clay pot rice" sprinkled with truffles.
(If you tell me the name under which you will make a reservation) I can communicate with them in advance so that they will definitely offer these signature dishes to you even for lunch. Thus, please definitely think this over.

The chef is from the same famous restaurant, Shoufukurou as chef Matsukawa of Tokyo. I heard rumors that the Kaiseki dishes utilizing wild game (bear, boar,duck) is exquisite and I have been thinking of visiting it for many years as well.
It's just that it takes 2 hours from Nagoya, which is much farther than going to Kyoto from Tokyo so I've not been able to fulfill it yet.
It seems to be a flexible shop so I think it is possible to make a reservation through the hotel concierge.

Thank you very much Saito San.

They accept reservations from first time visitors now.

can hotel concierges make a reservation?

Both restaurants accept reservations from first time visitors.

@Leo Saito Thank you.
Do you know how far in advance I should ask my concierge to make a reservation enquire?

I have heard that it is difficult to make reservations at the Nishibuchi Chinese restaurant unless you do so more than half a year in advance.
Sushi Sakai seems to only accepts reservations up to three months in advance, so please use that as a reference.

@Leo Saito
Thanks for your reply, although I was referring to Saika, the Chinese restaurant near Tofukuji, not Sushi Sakai

Oh!!!
Saika is intro-only.

@Leo Saito
I thought that might be the case. Thanks so much for your time.