Born in Nagano Prefecture and raised in Tokyo, Marie-Lou Hasegawa is a rising star in the Japanese Young Adult publishing sector. She received an honourable mention in the Kodansha Children’s Literature Newcomer’s Award for her work Oekaki kinshi no kuni (『お絵かき禁止の国』) and won the Japan Children’s Writers Association Newcomer’s Award for "Kasumigawa no ningyo"(かすみ川の人魚). Other notable works include "Manten in Samara Farm" (満天inサマラファーム), "Kinotori/Kanai: Nagasare mono no radio"(キノトリ／カナイ 流され者のラジオ), Sugimori-kun o korosu ni wa (『杉森くんを殺すには』, 2023)  and Sabaku no tabi garasu (『砂漠の旅ガラス』, 2023). Despite being an indoor person, she still enjoys engaging in various outdoor activities.