Bravo Larisa, you figured it out.
Chassalia curviflora is the only species of Chassalia native to Asia, and is likely most commonly cultivated species. The flowers are followed by black berries. What a beautiful plant. I'd love to grow one someday.
Chassalia is a genus of 108 species in the Madder Family (Rubiaceae), with most species native to tropical africa or Madagascar.
One species, Chassalia curviflora, is native to southern and southeastern Asia, Sri lanka, southern China, Hainan, Philippines, and Malesia.