credit to @MCplanes's for the fuselage.

The Korea Aerospace Industries KF-X/Indonesian Aerospace IF-X is a South Korean and Indonesian program to develop an advanced multirole fighter for the Republic of Korea Air Force (ROKAF) and Indonesian Air Force (TNI-AU), spearheaded by South Korea with Indonesia as the primary partner.[2] It is South Korea's second fighter development program following the FA-50.

The project was first announced by South Korean President Kim Dae-Jung at the graduation ceremony of the Korea Air Force Academy in March 2001. South Korea and Indonesia agreed to cooperate in the production of KF-X/IF-X warplanes in Seoul on July 15, 2010. The initial operational requirements for the KF-X/IF-X program as stated by the ADD (Agency for Defence Development) were to develop a single-seat, twin-engine jet with stealth capabilities beyond either the Dassault Rafale or Eurofighter Typhoon, but still less than the Lockheed Martin F-35 Lightning II. The overall focus of the program is producing a 4.5th generation fighter with higher capabilities than a KF-16 class fighter by 2020. Quantities of the resulting fighter are planned at 120 for the ROK Air Force and 80 for the Indonesian Air Force. South Korea plans to procure it from 2023 to 2030.