Yayoiso

Yayoiso is the pen name of the author of ReLIFE (Webcomic). Her real name, age, and looks are not made public, although she does hold autograph sessions with fans (photos of autograph events have her face redacted).

Her serialized works include ReLIFE and Yowamushi Resound (リザウンド).

See also: 夜宵草 on the Japanese wikipedia

Regarding her pen name

 * On her twitter account, her pen name is currently stylized as "YoyoiSo".
 * On her old homepage (last updated at the end of 2013, shortly after she started working on ReLIFE), her pen name is stylized as "Yoyoi-Sou".

On her old homepage she said that "even though 夜宵草 is a single entity, if you need to split it, split it as 夜宵/草 (Yayoi/Sou) and call me そうさん (Sou-san)".

Hence we can call her Ms. Grass.

Trivia

 * In various "No report." webcomic chapters, she depicts herself owning a red smart phone, just like the phone of the protagonist Arata Kaizaki.