A transaction processing system may include: a plurality of leaf chains including a first leaf chain and a second leaf chain, the first leaf chain and the second leaf chain including a first leaf chain manager contract and a second leaf chain manager contract, respectively; a root chain comprising a root chain manager contract for the root chain, a first leaf chain contract for the first leaf chain, and a second leaf chain contract for the second leaf chain; and at least one relayer located between the root chain and the plurality of leaf chains, and configured to process a remittance request from the first leaf chain to the second leaf chain.