Reservations at 3 Star Michelin Restaurants

Is there any other way to make a reservation at a 3 star Michelin Restaurant than asking a Hotel Concierge to perform the task about a month beforehand. I will be in Japan for a few days and reservations are just not available for these restaurants on the day I arrive.

Which restaurant specifically? And can you speak Japanese?

If hotel concierge cannot help, chances are low.
But you could try these services, fees may apply.

Pocket Concierge https://pocket-concierge.jp
Japan Table. http://www.japantable.com.au
Voyagin https://www.govoyagin.com/?lang=en&gclid=CNup-d_MytACFdcjvQod1L8CqA
Gurunabi https://gurunavi.com/en/a618100/tl/rst/

Some restaurants are fully booked months ahead, or regular customers only(although it's not publically said)
Just from curiosity, which restaurants and what date?

Thank you both for your prompt replies. I live in the USA and cannot speak Japanese. I would like to reserve seats at Ginza Kojyu in Tokyo on April 22. Will look into the services you suggested!