It is Park's feature film directorial debut and stars Go Eun-ah, Jeong Yoo-seok, and Chae Min-seo.

The film explores the phenomenon of hikikomori, a Japanese term referring to reclusive individuals who have chosen to entirely withdraw from the outside world.

Her bullied best friend, Lee Han-jeong is subjected to a cruel public prank that pushes her to commit suicide.

Upon hearing this, Se-jin talks to Soo-na through her bedroom door, stating that he left Song-i not because he stopped loving her, but because she was already married by the time he was discharged from the army.

[1] Loner was released in South Korea on 18 September 2008,[2] and on its opening weekend was ranked seventh at the box office with 45,710 admissions.

Whilst there are a few death scenes and some good use of special effects, the film is generally quite low key, and is arguably all the better for it, as this ensures that the psychological chills remain at the fore.