The jersey material runs throughout the entire inner surface of the knit. It is basically a double layer knit top.
BTW, I discovered that the cheaper junhashimoto knits are made in China while the more expensive knits are still made in Japan. This dual layer knit is made in Japan, but the basic merino v-neck I previously bought is made in China.
While I'm not keen on made in China, at least junhashimoto's pricing appropriately reflects the difference in production costs-- the MIJ knit costs double that of the MIC one.