Higurashi When They Cry: Cotton Drifting Arc, Vol. 1

You've already met Keiichi Maebara and his mischievous friends in the
Abducted by Demons Arc. But Oyashiro-sama's curse is poised to strike
anew in Hinamizawa village. When Keiichi spots tomboy Mion working at a
maid café, he can hardly believe his eyes! But it's not Mion after all
- it's her identical twin sister, Shion. Keiichi's never heard of this
"twin sister" before and suspects it's just another one of Mion's
pranks. But through Shion, Keiichi is able to see a quieter, more
feminine side of his best friend, even if it is all an act. As Keiichi
spends more time with Shion, however, Rena grows more accusatory...