Transmigration: I Became the Japanese Army's Top Interpreter

System + high intelligence + killing Japanese invaders. After transmigrating to Republican-era China, he becomes the Japanese army's chief interpreter and is denounced as a traitor by the entire nation!

Luckily, he binds to an undercover System, disguises himself as a spy in enemy ranks, steals secrets, outwits their schemes, and fights with his life to defend his homeland!