Geourui Gyeonggye

Won-Hee and Seo-Won, who became brothers due to their parents' remarriage. At some point, everyone around Won-Hee falls into misfortune and starts leaving Won-Hee one by one. Won-Hee draws a line between himself and everyone except Seo-Won, who stays by his side. Then, Geon-Ho, who is known for his frivolous behavior, appears in front of him...

(Source: Lezhin, translated)

Note:
- Chapter count includes a prologue.
- Part of Lezhin's Gwanggong Collection (광공단편선). A gwanggong (광공, hanja: 狂攻) character is obsessed with the object of their desire, similar to the Japanese "yandere". Scanlations have erroneously translated this to "GwangGong Apartment/Industrial Complex", which may have caused confusion.