Silver Guardian: Seasons 1 & 2

Suigin Riku is a student at the prestigious Shinryou Private Academy. Struggling to make ends meet, he fills his schedule with part-time jobs and sessions of his favorite MMORPG, Dungeon Century. In-game, he meets a girl from his school, Rei Riku, who's the daughter of a renowned tech developer. But after adventuring with her for weeks, the game's servers shut down to make way for the latest world-altering title. Grave Buster—a video game proclaiming "reality beyond reality" hits the shelves, and Rei is pulled into it by forces unknown. Now it's up to Suigin to rescue her from the virtual world, no matter the cost.