Leo grew up in an abusive environment, witnessing his parents' constant fighting and his baby sister's tears. He adored his sister Sol and became her caretaker after their parents separated. To hide his troubled past, Leo joined a group of troubled kids and became a bully. This behavior continued into university, where he targeted a boy named Muse. Muse, who had lost his parents, suffered in silence and expressed his emotions through music. Dean, a top student, discovered Muse's music and was deeply moved by it. New chapter: Sunday