The Other Boy by M.G Hennessey (ages 8 to 12)

Shane Wood is just a baseball playing, video game loving, and comic book drawing 12-year-old boy. But he is also living a stealth life as a transgender boy. No one at the school knows Shane was assigned female at birth and lived a life as a female for years—not even his best friend. But a classmate uncovers his truth and outs him. Shane is supported by his mother, but he needs to know if he will be supported by his best friend and his teammates too.