“Protocol: Rain” follows the journey of Shun Tokinoya in his journey to becoming a professional e-sports player. Shun lost his father in an accident, forcing him to work at an e-sport café to support his mother and sister. Things take a turn when the debt-burdened owner of the café requests that he and his friend join his e-sports team and win the “Xaxerion Championship” to pay off all debts.