In Japanese spelling Un DOES sounds like An, Akari just write it in accordance to Japanese spelling of the word one in french. It's like writing Ichi(one in Japanese) as Eechee because if it's written as is it would be read as aichee in English.
Thats why at some part cinq is written as senku, Japanese write cinq according to how it's pronounced. Senku is the closest Japanese alphabet could get to pronounce cinq
Aaah I see. It makes sense in a lot of culture. Japan often use number to name their kids, Ichiro, Jiro, Saburo it's all meant just 1st son 2nd son 3rd son. In my culture too, Eka, Dwi, Tri (archaic word for 1,2,3) are all commonly use to name their kids. People who call them already recognize it as name instead of numbering so.. it doesn't feel less humane. It felt similar to naming your kids month name, like April or Augustus,
It's very unconfortable how she keeps naming her children numbers. An is the wrong speling but same prononciation as un, which is one in French. Deux is two... And so on...