Rubus hayata-koidzumii is probably better known by the (illegitimate) synonym Rubus calycinoides or as Creeping Raspberry. It is a low-growing member of the genus Rubus which also includes better known edibles such as the blackberry, raspberry, boysenberry, and thimbleberry.
Originally from Taiwan where it grows at high elevations.
Like other plants in this genus, creeping raspberries bear aggregate fruits. What this means is that each "fruit" is actually a cluster of small fruit-like parts (pistils) connected together into one mass. Creeping raspberry fruits are similar in appearance to blackberries or red raspberries, but differ in that their color is yellow to orangish-red. The edible fruits follow white flowers which are borne in early summer.
This plant can be susceptible to overwatering, however, which can cause root rot in wet or heavy soil and good drainage is important.
The names Rubus pentalobus and Rubus rolfei are sometimes used in place of R. hayata-koidzumii or R. calycinoides. There are a number of other common names including "Crinkle-leaf Creeper", "Taiwanese Creeping Rubus", and "Creeping Bramble",  but the plant is also often simply referred to by cultivar names such as 'Emerald Carpet'.