Reunion and Restart - S1.E1

In the online RPG "Union" was Subaru, a party of grade school players. One day, two of its members Asahi and Haruto exchanged a promise and a ring. But Asahi sacrificed herself to protect Haruto and also died in real life. The game then suspended operations and the members of Subaru went their separate ways. Six years later, Haruto logs into the newly released "Re'Union" and reunites with Asahi.