Chicago High Roller

In the 21st century, an office worker travels through time to Chicago in 1947 while taking a shower, and is mistaken by a female mafia boss for the top assassin 'Jade-faced Yama' who has been missing for ten years. After a one-night stand, he is forced to continue playing this cold legend, using modern knowledge to show off and slap faces all the way. Just as he gains a firm foothold and captures the female boss's true heart, the real Jade-faced Yama—his twin brother—returns. And that woman has had a secret crush on his brother for a full ten years.