Geum Na-ra was once a top-ranked investment banker, until his life falls apart when his debt-ridden father commits suicide after constantly being harassed by loan sharks.

However, realizing the only way to defeat his enemy is to understand the enemy, Na-ra decides to become a loan shark himself, and begins working as a ruthless money collector for the notorious loan shark Ma Dong-po (Lee Won-jong), while learning the trade secrets along with life's philosophies from the old and legendary pro Dokgo Chul (Shin Goo) who reluctantly takes Na-ra under his wing.

Joo-hee was supposed to marry a divorced man to solve her family's financial problems, but on the day of the wedding, Na-ra showed up to collect the debts and ended up ruining her plans.

When Na-ra learns that his gangster boss Ma Dong-po was the very man responsible for his father's death, he keeps his cool, waiting for the right time and the right place to seek his revenge.

Because of the series' high viewership ratings of over 30%, SBS filmed an additional four episodes featuring new characters and a new plot not found in the original comic, titled War of Money Bonus Round.

[11] A Japanese drama remake also titled War of Money (銭の戦争, Zei no Senso), starring Tsuyoshi Kusanagi and Yuko Oshima, will air on Fuji TV in January 2015.