is he french ?
You're probably asking that because their name litteraly means "milk-flavored mochi".
I'm almost sure they aren't french. However, japanese people are fond of french culture, language and such, and that's why you often find in anime french-inspired characters (I have 3 different ones in mind featuring Gille de Rais lol) and why you can hear them say some french expression. This author's nickname is pretty surely an implied reference to our french culture ;)
On a side note, I love this author, they deserve to be published like regular yuri authors do.