Question: What Kim Go-eun film was a South Korean martial arts/romance?

Context paragraphs:
Kuk Sul Do: Kuk Sul is a Korean martial arts style that was brought to the United States by Choon S. Yang.  The name "Kuk Sul Do" translates to "National Korean Martial Art", and was put together from a number of different Korean martial art styles in order to preserve traditions and movements that are thousands of years old.  Because of Kuk Sul Do's beginning, it is a well-rounded traditional style that doesn't necessarily have any specific weaknesses, and encompasses a large amount of material and tradition.

Kumdo: Kumdo is a modern Korean martial art derived from Japanese Kendo. its origin is the Japanese kendo.  Though romanized in a number ways when written Kǒmdo or Geomdo the meaning remains "the way of the sword" and is cognate with the Japanese term.  As a martial art, Kumdo has become accepted in Korean culture and society since its introduction from Japan to the degree that the term "Kumdo" has, in recent history, become a generic label for other Korean martial arts based upon swordsmanship.  As a result, caution should be exercised to avoid confusion among practices espousing martial (i.e., Hankumdo) rather than sporting and competitive goals.  Although related to Japanese Kendo, minor differences exist in Korean Kumdo due to appropriation and acculturation.  Such differences include, but are not limited to, the use of native terminology, the use of blue flags rather than red flags for the referees and minor modifications to the uniform.

Memories of the Sword: Memories of the Sword (; lit.  "Female Warrior: Memories of the Sword") is a 2015 South Korean martial arts/romance period drama co-written and directed by Park Heung-sik, starring Lee Byung-hun, Jeon Do-yeon and Kim Go-eun.

WonHwaDo: Won Hwa Do(원화도) is a traditional Korean martial art, founded in 1972 by Bong-Ki Han.  The name in Korean (Hangul) means "The Way of Circular Harmony" (Won = Circle, Hwa = Harmony, Do = Way).  The basis of the art lies in circular movement by effectively utilizing full 360° rotations of the human body motion.  This helps in conserving energy and reducing the risk of injury on the practitioner's joints often caused by use of linear force and impact.  Won Hwa Do is often compared to hapkido and Taekkyeon which are also national martial arts of Korea.  Although similar in several aspects, Won Hwa Do's Ha-Dan/Sang-Dan Hoe-Jeon-Gong-Bang (하단/상단 회전공방) techniques are a unique trademark which is not shared by the other Korean martial arts.  Ha-Dan Hoe-Jeon- Gong-Bang has the practitioner rotating arms in a forward motion and Sang-Dan has them rotating it in a backward motion.  These two form the bases of strikes, throws, blocks, counters, submissions and kicks in its diverse self-defense system and are the most fundamental and basic practice of Won Hwa Do.

Kuk Sool Won: Kuk Sool Won () is a Korean martial arts system founded by Suh In-Hyuk (), the "kuk sa nim" (grandmaster) in 1961.  The name "Kuk Sool Won" translates to "National Martial Art Association" and despite often being shortened to "Kuk Sool", the name "kuk sool" (국술; 國術) is a non-trademarked name used to denote similar Korean martial arts developed prior to or about the same time as the formation of Kuk Sool Won.  Kuk Sool Won is currently taught world-wide and since it was founded as a martial arts system and not merely as a martial arts style, Kuk Sool Won does not consider itself limited to any single discipline.  It attempts to be a comprehensive study of all traditional Korean martial arts.  Suh In Hyuk's philosophy regarding his system is to "Integrate and explore the entire spectrum of established traditional Korean martial arts, body conditioning techniques, mental development, and weapons training."

Sang Kee Paik: Sang Kee Paik (1929–2009), also known in Korean reference as Paik Sang Kee, was a South Korean martial arts grandmaster and creator of a Kwon Bup system he called Sa-Sang Kwan (Korean: school of the four natural elements: air, earth, fire, and water).  Paik was one of the first pupils to receive the black belt under Yoon Byung-In, and Kim Ki Whang with whom he continued his training after Yoon's disappearance during the Korean War.  Paik's system of Sa-Sang built upon the Ch'uan Fa (Korean: Kwon Bup) he had mastered under Yoon Byung-In, and included elements of Shudokan karate from both Yoon and Kim.  Paik completed the system with his research into training effective kicking techniques.  He created four primary forms (Korean: hyung), symbolizing each of the four natural elements.  He also developed a rigorous philosophy unique to the system, and intended to be carried into one's everyday life.

Kim Go-eun: Kim Go-eun (born July 2, 1991) is a South Korean actress.  She debuted in the critically acclaimed film "A Muse" (2012) where she won several Best New Actress awards in South Korea.  She next appeared in the crime thrillers "Monster" (2014), "Coin Locker Girl" (2015) and "Memories of the Sword" (2015).  Kim then extended her filmography to television where she played leading roles in the tvN dramas "Cheese in the Trap" (2016) and "" (2016-2017).

Kim Ki Whang: Kim Ki Whang (1920 – September 16, 1993), also known in the United States as Ki Whang Kim, was a Korean martial arts grandmaster.  He was Chairman in the US of the Tang Soo Do Moo Duk Kwan Association, Chairman of the US Olympic Taekwondo team 1988 and helped unify several Korean martial arts into the overall style of taekwondo.

Korean martial arts: Korean martial arts (Hangul: 무술, Hanja: 武術, "musul" or Hangul: 무예, Hanja: 武藝, "muye") are military practices and methods which have their place in the history of Korea but have been adapted for use by both military and non-military personnel as a method of personal growth or recreation.  The history of Korean martial arts can be traced as far back as the prehistoric era.  The ancestors of modern Korean people migrated and settled in the Korean Peninsula as early as the 28th century BC, a geopolitical region besieged by thousands of known documented instances of foreign invasions.  Consequently, the Korean people developed unique martial arts and military strategies in order to defend themselves and their territory.

Midnight Blue Belt: Midnight Blue Belt is a belt worn in some Korean martial arts to signify that the wearer has attained "dan" rank, which translates to a degree holder.  This belt is most commonly seen in the Korean martial arts of tang soo do and soo bahk do, where it is often used in place of the more common black belt.  Its origin lies in Hwang Kee, who used it to denote "dan" holders in the Soo Bahk Do Moo Duk Kwan.  In tang soo do, black is viewed as a colour that does not become darker, and thus signifies an end (death), whereas midnight blue represents more positive concepts, such as the element of Water.

Supporting paragraphs: Kim Go-eun Memories of the Sword
Answer: Memories of the Sword