Director and writer Yukiko Motoya was born on July 14, 1979, in Ishikawa Prefecture.
After graduating from high school in Ishikawa, she moved to Tokyo and enrolled in the ENBU Seminar, a vocational school that trains film and theater professionals. She appeared in stage productions such as "Fukusuke" by Suzuki Matsuo's theater company, "Otona Keikaku," as well as "alt.4" and "1989." In 1998, she made her voice acting debut as Sawada Aya in the anime "His and Her Circumstances."
In 2000, she founded the "Motoya Yukiko Theater Company." Based on the concept of a "production unit" without dedicated actors, she began her career as a playwright. Her unique worldview, centered around delusional characters, gradually attracted fans, and in 2007, she became the youngest recipient of the 10th Tsuruya Nanboku Drama Award for her play "Sōnan," and in 2009, she won the award for "Happiness, Thank You So Much! Her novel "Eriko and Absolute" won the 53rd Kishida Kunio Drama Award. Meanwhile, in 2002, she published her novel "Eriko and Absolute" in Ecstasy, a supplement to the monthly literary magazine Gunzo, marking her debut as a novelist. In 2005, her novel "Show Me Your Sad Love, You Cowards" was nominated for the 18th Mishima Yukio Prize, and the following year it was made into a film starring Sato Eriko. This work was officially selected for the Critics' Week at the Cannes Film Festival. Motoya continued to publish numerous novels, including "Just Being Alive Is Love" and "Lukewarm Poison." In 2013, her novel "Picnic in the Storm" won the 7th Oe Kenzaburo Prize, and the following year, her novel "How to Love Yourself" was selected for the 27th Mishima Yukio Prize. Her appearances on radio programs also played a role in increasing her profile. From 2005, she was a personality on Nippon Broadcasting System's "All Night Nippon" for one year. She gained a core following for her special episode "Otaku Night Nippon," her tendency to misread kanji characters despite being a writer, and her tolerant attitude toward vulgar jokes, but the show ended after one year as it was deemed "an example to set an example."

In part due to these activities, she was selected as "Vogue Nippon Women of the Year" in 2009, which selects Japan's most representative women. In her personal life, she married poet and lyricist Okachimachi Tako in 2013.