The Famicom Mini has a special message hidden in it’s code and IGN shared what it stated.

“This is hanafuda captain speaking. Launching emulation in 3..2..1. Many efforts, tears and countless hours have been put into this jewel. So, please keep this place tidied up and don’t break everything!
“Cheers, the hanafuda captain.”

Could be a message not to hack the system or mess with it’s coding, so that is a nice little touch the JP version of the NES Mini has present within the console.