7:43 AM PT -- Tenshin just responded to Conor ... and laid out his terms for a fight with the UFC star.

"Dear Mr. McGregor, Thank you very much for remembering my name. I’m honored that you would even consider fighting me," Tenshin said.

So, what kind of a fight does Tenshin want?

Weight -- 58 kg (128 lbs).

Fight Rules -- kickboxing rules.

Tenshin says these are the demands that "would probably get us in the ring sometime in the near future."

The problem ... Conor ain't 128 pounds. He weighed in at 155 lbs to fight Khabib back in October and hasn't fought at 145 since Dec. 2015.

$9 million for 2 minutes of work??

Conor McGregor wants some of that action -- which is why he's calling out Tenshin Nasukawa ... the guy who got his ass kicked by Floyd Mayweather on New Year's Eve.

"I wish to go to Tokyo to face Tenshin Nasukawa in a Mixed Martial Arts exhibition bout," McGregor said in a note to the UFC and his agents at Paradigm Sports Management.

"Before this summer. Please arrange this, this instant. Yours sincerely, The champ champ."

The Tenshin vs. Floyd fight was supposed to be a 3 round exhibition -- but Tenshin's corner threw in the towel with 41 seconds left in the 1ST ROUND after Floyd knocked him down multiple times.

Some people think the fight was fixed and Tenshin took a dive ... but Conor doesn't seem to care -- all he sees is EASY MONEY!

Remember, McGregor made $100 million to box Floyd -- but LOST when the fight was stopped in the 10th round.

McGregor then made around $50 mil to fight Khabib Nurmagomedov ... but tapped out in the 4th after getting mauled by the Dagestani.