Naeka's friend and fellow teammate in the kendo club. They are usually seen eating lunch together or at practice with Miwa. Eiko is usually the first to yell at her busty classmate for her shallow or selfish comments. At the same time, Eiko does enjoy her friendship with Naeka, scheming for their kendo club, wanting in on the latest gossip, or needing help with the maid cafe where she and Miwa works.