I saw a comment under a video which says the following:
A: I’m not sure but wasn’t menma half japanese half russian?
B: yes. the father is japanese and the mother is russian.
C: well, that's explain why she's the only one with unique hair in the anime
D: I’ve noticed in anime if you russian you have gray-ish hair. For example Viktor (Yuri on ice), Lev and Elisa (Haikyuu) and Menma
This is somewhat correct as Irene Honma (mother of Menma) is non-Japanese. But is she actually Russian? There is no mention of Irene being Russian in wiki apart from a note that says:
The name Irène means "peace" in Greek.
Question: Is there any information in source material(manga) regarding the actual ethnicity of Irene Honma? If so, is she Russian?
Related discussion: Is it known whether Kaori Miyazono is half-Japanese?