Eri (えり) is a Black Delmo member.
Eri has long black hair. Alongside her Black Delmo uniform, she is seen in casual clothes including a pink summer dress and white heeled shoes.
Eri was among the group of Black Delmo which attacked Aika and Gust in the underground parking lot, led by the Black Delmo Leader. Aika knocked her down with a leg strike to her stomach, right after Misaki.
Afterwards, Eri reappears during the unsuccessful attempt by the Delmo Corps to eliminate Aika during her vacation at Peroronka Island. In that occasion, she, Naomi and Misaki are the ones in charge of capturing Rion while Valerie distracts Aika. Misaki starts by distracting Rion, asking her the way to the elevator. Then, before Rion could react, Eri and Naomi pulled her to some hotel room. Later she is seen drinking coffee at a table with Misaki and Rika in the hotel's restaurant, discreetly observing Aika and "Pierre Valimore" sitting at another table nearby.
After some time she is seen again as part of a Delmo group, this time led by Bianca, which confronts Aika in her hotel room, revealing their true identity. However, Aika manages to escape from them by jumping down from her room's balcony, freeing Rion Aida and Shuntaro Michikusa in the process, so Bianca's group begins a pursuit. After some running, Aika and her friends are forced to fight the Delmo in the hotel's kitchen, making quick work of all of them.
During the fight, Eri puts up a moderately decent effort, at least trying to go for a kick against Aika, which is nonetheless easily evaded by the salvager. Subsequently, Aika returns the favor and demolishes the Delmo with a far more precise double feet kick right in the stomach, which sends the poor girl flying acroos the room, landing hard with her back against the border of a counter filled with stacked dishes. As the girl crumbles to the floor due to the blow, the impact also causes the piles of plates to collapse on top of her, hitting her as she falls. It is unclear if by that point she was already unconscious or if the falling dishes finished the job. She was the third girl to fall.