Book  (2019)  Page(s) 133.  Includes photo(s).
 
Rosa chinensis Jacq. 'Koushin Rose', description

Article (magazine)  (2017)  
 
The wild-type homologue of the recessive gene for seasonal flowering in roses has been named RoKSN, where Ro stands for rose and KSN for “Koushin”, the ancient Japanese name for recurrent-flowering Rosa chinensis (Iwata et al., 2012). 

Book  (2013)  Page(s) 165.  
 
Ogisu (1996) has provided an accessible treatment of roses in China's traditional horticulture. Records of rose growing are known from the sixth century A.D. and from the Song and Ming Dynasties. The Koushin rose, apparently recurrent flowering, had arrived in Japan by either the Sui or Tang dynasties, more than 1000 years ago. 

Article (magazine)  (2012)  Page(s) 17-18.  
 
 The Koushin (“every other month”) rose of Japan, for example, imported from China over a thousand years ago, is quite distinct from the specimen of Gronovius and Jacquin, yet both are R. chinensis, with their defining characteristics and cultivated history.
Peter Osbeck, a pupil of Linnaeus, identified a similar specimen in the gardens of the Custom House at Canton , China in 1751. It became his type specimen for R. indica and yet is certainly R. chinensis, probably identical to the “Blush Tea China ” in Linnaeus’ herbarium. 

Magazine  (Sep 1996)  Page(s) 154.  
 
Chinese roses were brought to Japan a long time ago. It is said that a kind of rose called 'Koushin' in Japanese had already arrived by the Heian era (794-1192 A.D.), so, presumably, it crossed the ocean ..