MasteNodes provide added security to the Ichiba network. MasterNodes receive part of the block reward for exchange for their services as full network nodes. As full nodes, masternodes host and maintain the entire blockchain and have the ability to reject blocks of transactions as they see fit.
To become a MasterNode on Ichiba, you must run a full blockchain node and provide a minimum 5,000 ICA coins as collateral. Masternode holders are also given the opportunity to vote on network proposals as they arise.