The two shops appeared on Thursday, slotted into a basement window in a small street in the city, Rue des Visitandines.
The Agent de Voyage Anatole looks like a travel agent from a by-gone age, with elegant lettering and the logo of a soaring dove, while the Sacreblues jazz club – in true hipster fashion – has mouse-sized chairs made out of repurposed beer bottle tops, and tables made from champagne corks.
Anonymouse's brilliantly original street art created a social media sensation when the first meticulously constructed miniature shops appeared on Malmö's Bergsgatan in December 2016, with their mysterious appearance reported in more than 30 different countries.
Announcing its new French venture, the anonymous group said they had been excited to discover that a part of Bayonne was called Petit Bayonne.
"And we found that in Petit Bayonne, there is also a Petit-Petit Bayonne. And in Petit-Petit Bayonne there is an excellent travel agent called Anatole; and a jazz club called Sacreblues. So if you happen to be in the south of France, check it out!"
Shortly after the first shops appeared in Malmö in 2016, the mice opened the Tjoffsans Tivoli fairground on Södra Förstadsgatan, another Malmö street.
Then in September last year, they opened an antiquity and textile business in the Swedish city of Borås.
Yasha Mousekewit (not his or her real name), said that the decision to branch out to this part of the Basque country had come in connection with the Points de Vue street art festival in the city.
"Since we got to do a bit of travel, it only seemed fitting to present the mice of Bayonne with the same chance, so that's how the travel agency came to be," the mouse artist wrote in an email to The Local.
"And from Django Reinhardt to Josephine Baker this part of the world has always had a great appreciation for jazz. Also, the name of the club was a great pun," they added. "We hope the little stores will last at least during the weekend, but you never know!"