The emergence of non-volatile memory (NVM) presents opportunities for making its in-memory data of application programs persistent at a small cost. An adequate abstraction is required for programming languages to be able to utilize NVM. Here, persistence by reachability is a suitable abstraction for managed languages. In this abstraction, all objects are volatile when they are created and become persistent later depending on reachability from the predefined roots. The state of the art in this area creates objects in DRAM and move them to NVM when they become persistent. This implementation has two inefficiencies. One is the read barriers to get the current location of objects, and the other is reading from NVM, which is slower than DRAM, to read from persistent objects. In this paper, we propose a new algorithm to realize persistence by reachability. The proposed algorithm does not move objects to NVM to make them persistent. Rather, it creates replicas of the objects in NVM. After replication, the original copy in DRAM is kept synchronized with the replica. The program can obtain the contents of a persistent object by reading from DRAM without read barrier. We preliminarily implemented it in the HotSpot VM of OpenJDK and evaluated its overhead. The results showed that the overhead of making objects persistent was 2.7% on average, the overhead of writing to persistent objects varies from 0.4% to 335.5% depending on write frequency, and the overhead imposed on programs that do not make any object persistent was similar to the previous work.