Erika Koike (小池（こいけ）えりか) is Hikage Miyakawa's classmate. She debuts in Episode 4 of Miyakawa-ke no Kufuku. She is voiced by Kanae Iwasaki.
Appearence and Personality
Erika has yellow-colored hair which she ties it into a ponytail and has blue eyes. She is called "eririn" (えりりん) by Hikage and "Eri-chan" (えりちゃん) by Yukina. She is interested in romance. She has an elder brother.