This is a story about guns and swords, and also about a slacker and an abacus.
When the "First Gun" becomes a disgrace to his family,
when a slacker runs into a fox who plans for every contingency.
He is the good-for-nothing second-generation gunner abandoned by the whole world.
She is the third-in-command of Tu Shan, who calculates every debt down to the last detail.
A desperate escape, a rescue with a clearly stated price.
What he thinks is fate is a deficit waiting to be filled in her ledger.
And so...
The good-for-nothing starts working to pay off an astronomical bill,
while the abacus can't calculate how this debt keeps accruing interest in love.
When a rusty gun is polished bright by the hands that wield the abacus,
what they'll pierce through is more than just the sky above them.
