Shun quit gaming to keep his family afloat after his father died. Now he has to win a tournament to save the café that's been keeping them alive. Protocol: Rain doesn't fake the weight of that choice, it refuses to let you enjoy victory without feeling what it costs him to get there, and that's what separates it from every other esports anime that mistakes competition for drama.

Shun Tokinoya, a high school second-year, shares a home with his mother and his younger sister. After an accident killed his father and injured his sister, he gave up the online game he loved. He now fills his days with studying and part-time work at FOX ONE, an esports café run by the family of his childhood friend Nozomi Inatsuki. When he learns that the café is buried in debt, Shun and his friends decide to enter the Xaxerion Championship and go after the prize money. Weighed down by guilt, Shun reluctantly returns to online gaming, where he comes face to face with Bakuretsu-kun, a player he used to play alongside. With classmate Akito Sendou, the group sets out to find skilled players and rebuild the team, but their hastily assembled squad has little chance unless Shun can let go of his remorse.