Question: Pencil is based on a 2009 South Korean thriller film that starred Yoo Seung-ho and who else?

Context paragraphs:
4th Period Mystery: 4th Period Mystery (), released internationally as The Clue, is a 2009 South Korean thriller film starring Yoo Seung-ho and Kang So-ra.

Imaginary Cat: Imaginary Cat () is an 8-episode South Korean television series starring Yoo Seung-ho.  It aired on cable network MBC Every 1, every Tuesday at 20:50 (KST) from November 24, 2015, to January 12, 2016.

Homo Academicus: Homo Academicus (Hangul: 공부하는 인간: 호모 아카데미쿠스 ) is a South Korean documentary television program broadcast by Korean Broadcasting System (KBS).  It is narrated by Yoo Seung-ho, and hosted by Lilli Margolin, Scott Yim, Jenny Martin, and Bryan Kauder.

Operation Proposal: Operation Proposal () is a 2012 South Korean television series starring Yoo Seung-ho and Park Eun-bin.  It aired on TV Chosun from February 8 to March 29, 2012 on Wednesdays and Thursdays at 20:45 for 16 episodes.  It is a remake of Japanese drama "Operation Love" (プロポーズ大作戦 , Proposal Daisakusen ) that aired on Fuji TV in 2007.

Yoo Seung-ho: Yoo Seung-ho (; born 17 August 1993) is a South Korean actor who rose to fame as a child actor in the film "The Way Home" (2002).  After his two-year mandatory military service, he headlined the legal drama "" (2015) and historical films "The Magician" (2015), "" (2016), as well as historical drama "" (2017).

Warrior Baek Dong-soo: Warrior Baek Dong-soo () is a 2011 South Korean fusion historical/action television series starring Ji Chang-wook in the title role, with Yoo Seung-ho, Yoon So-yi, Shin Hyun-bin, Choi Min-soo and Jun Kwang-ryul.  It aired on SBS from July 4 to October 10, 2011, on Mondays and Tuesdays at 21:55 for 29 episodes.

Master of Study: Master of Study (; lit.  "God of Study", "Lord of Study") is a South Korean television series that aired on KBS2 from January 4 to February 23, 2010 on Mondays and Tuesdays at 21:55 for 16 episodes.  It starred Kim Su-ro, Bae Doona, Oh Yoon-ah, Yoo Seung-ho, Go Ah-sung, Lee Hyun-woo, Park Ji-yeon,

The Emperor: Owner of the Mask: The Emperor: Owner of the Mask () is a South Korean television series starring Yoo Seung-ho, Kim So-hyun, Kim Myung-soo, Yoon So-hee, Heo Joon-ho and Park Chul-min.  It aired on MBC every Wednesday and Thursday at 22:00 (KST) from May 10, 2017 for 40 episodes.

Pencil (film): Pencil is a 2016 Indian Tamil mystery thriller film written and directed by debutant Mani Nagaraj and produced by S. P. Ragavesh.  The film is based on South Korean film "4th Period Mystery" released in 2009.  The film features G. V. Prakash Kumar and Sri Divya in the lead roles, with the former also composing the film's music.  The film was released on 13 May 2016.

Blind (2011 film): Blind () is a 2011 South Korean crime thriller film directed by Ahn Sang-hoon with screenplay by Choi Min-seok which won the "Hit By Pitch" project fair held by the Korean Movie Producers Guild in 2009.  It stars Kim Ha-neul and Yoo Seung-ho.  Kim received Best Actress honors at the 48th Grand Bell Awards and the 32nd Blue Dragon Film Awards for her performance.

Supporting paragraphs: Pencil (film) 4th Period Mystery
Answer: Kang So-ra