The Regressed Extra Becomes a Genius

Read Manhwa The Regressed Extra Becomes a Genius / 회귀한 엑스트라가 천재가 됨 / The Extra Who Returned Became a Genius Kim Seonwoo, who fell into a novel and lived quietly as an extra. One day, the protagonist of the novel died. "...You expect me to believe this?" He returned to the past. To the very first day he fell into the novel. A mere extra like me has to protect the protagonist?!