The "Extra Quality" moniker attached to this release is not just marketing fluff; it is the product's strongest selling point. Acerola has always prioritized fluidity over strict anatomical realism, and Chika V100 is the zenith of this philosophy.
"Sister" can mean:
Thus, "NTR Sister Chika" = a little sister character named Chika involved in a Netorare plot. ntr sister chika v100 acerola extra quality
Acerola, also known as Barbados cherry or West Indian cherry, is a fruit native to South America, Central America, and the Caribbean. It is famous for having one of the highest concentrations of vitamin C (ascorbic acid) of any fruit—up to 100 times more than an orange by weight. The "Extra Quality" moniker attached to this release
If you arrived here searching for that keyword, try these corrected searches: Thus, "NTR Sister Chika" = a little sister
Given the "Sister" addition, the most likely is a custom character in a game like Koikatsu Party or Honey Select, where users can create "Chika" as a sister character and label scenarios as NTR.
Again, no standard definition exists.