I guess the thing which she's holding isn't a folding fan, so I'll need somebody's help with recognising it.

Raisa Pottgen, http://danbooru.donmai.us/post/index?tags=raisa_pottgen not Erica. Erica has shorter hair. Also more likely that Raisa would have such an accessory.

Sorry, I looked at previous youkan's works and she looked mostly like Erica except her hairstyle.

HNTI said:
I guess the thing which she's holding isn't a folding fan, so I'll need somebody's help with recognising it.

It's some kind of bat used for a certain Japanese badminon game usually played on New Year.
http://www.japan-guide.com/e/e2261.html
tag: hanetsuki

makkun said:
It's some kind of bat used for a kind of Japanese badminon game usually played on New Year or other holidays.
http://www.japan-guide.com/e/e2261.html

Thanks a lot :)