Yu Ashino (芦野由宇 Ashino Yū) is Arata Wataya's neighbour in Fukui.
Yu is of average height, with short black hair with bangs and brown eyes. She wears her navy blue sailor fuku-style school uniform. During cold weather she adds a pink scarf and a beige cardigan.
Yu and Arata are schoolmates and childhood friends. He tried to convince Yu to start a karuta club with him, but she said no.
- She used to play karuta back in elementary school.