PROTOCOL: RAIN

The story centers on Shun Tokinoya, a second-year high school living with his mother and younger sister. After his father's death in an accident and his sister's injury, he quit the game he was passionate about, and now works at an esports café called "FOX ONE." He spends all his time studying and working part-time while hanging out with his childhood gaming friends. Suddenly, he learns that "FOX ONE" has a huge amount of debts. In order to repay the debts, Shun and his friends aim to win the "Xaxerion Championship" and win the prize money. With a sense of guilt, Shun jumps back into the world of online games, and is confronted by Bakuretsu-kun, who used to play the game with him. (Source: Crunchyroll) — Description from AniList community (anilist.co).