A Thousand Blues by Seon-Ran Cheon

2035: In the shadow of a race course, a young woman finds a robot named Coli on a scrapheap. Intrigued, she takes him into her care, and learns how he is designed to be a humanoid jockey. She and Coli are determined to rescue his beloved horse who is heading for the knackers' yard. To remind the horse of happier times, they hatch a special plan to let her run another race. But it will be no ordinary event - they will train her to run the slowest time of her life. In the heat of the race, Coli feels the horse running too fast. She is in pain and will soon injure herself. To save his friend, Coli will commit one final act of bravery.