Steins;Gate 0

Synopsis

With each attempt at saving Mayuri and Suzuha failing, Rintaro deduces that they need to stop the Russians from interfering with the time machine's departure. Finding that Russia's ability to make a time machine lies with Kurisu's memory data, Amadeus Kurisu proposes that the only way to stop Russia is to use Daru's D-RINE (a custom app-messaging system that can send D-Mails without them being detected by SERN) to send a message to himself in the past to delete Amadeus. Speaking with a hesitant Rintaro through the night, Amadeus Kurisu tells him that she would be glad to sacrifice herself if it means finding Steins;Gate. After Amadeus Kurisu says her goodbyes to everyone, the D-RINE is sent, erasing Amadeus and sending Rintaro to a new world line.

(Source: Wikipedia)