Izumi Shimomura is the 27th chapter Ajin: Demi-Human, created by Gamon Sakurai.
The chapter starts with Izumi Shimomura waking up and going onto her veranda and begins reminiscing about her past.
19 months earlier, Yū Tosaki visits a dying Izumi in the hospital informing her that she is an unconfirmed Ajin and that both her mother and step father have died.
During her third year of high school Izumi constantly worked at a convenience store and her step father was an alcoholic. Izumi questions her mother why she is with a man like him. Izumi goes to sleep looking at her bank account eagerly awaiting the day she can leave home.
At school her friends comment that she looks exhausted which she quickly dismisses before going to meet her boyfriend, Kazuki. He asks Izumi to move in with him after they graduate which she happily agrees to.
Later that evening, Izumi checks her bank account to discover that almost all of the money she had been saving disappeared. Izumi confronts asks her step father about this who confesses that the money was spent on girls. Izumi angrily confronts her mother asking why she can't just be satisfied with her. Emotionally hurt, she goes to meet Kazuki only to discover that he was cheating on her with another girl.
She goes home and cuts her wrists with some scissors where her drunken step father found her and sexually haressed Izumi. She grabs the scissors and stabs him in the shoulder with them and he retaliates by hitting her head against the sink.