Origin appears to be post #3923564 (posted 2019-07-02), however the meme exploded in popularity in May 2020.
Some Twitter artists are using the tag for "redraws" of Tsuki ni Kawatte Oshioki Yo. For Danbooru purposes, do not add the tag unless combined in the art.
Origin
The original screencap
Earliest known redrawn
The episode has a scene where Sailor Moon is tossed to the ground by Sailor Neptune and Sailor Uranus after Mistress 9 deceives her into thinking they are going to defend her. Sailor Moon realizes she's been deceived and stares up at Mistress 9 from the ground, tears welling up in her eyes.
