Motoko Arai (????, born 1960 in Nerima, Tokyo) is a Japanese science fiction and fantasy writer. Her first novel received an award in 1977 when she was in high school. In 1981 and 1982 she received the Seiun Award for short fiction. She graduated from Rikkyo University in 1983. Her works have also been filmed.Arai is on the selection committee for the annual Super Dash Novel Rookie of the Year Award.