Cashback System

A man is treated as a mere tool by his wife and daughter, enduring a life worse than a pet's. When a heart attack strikes, they refuse to sign for his surgery, dismissing it as a scam. After awakening a system that grants him tenfold returns on every purchase, he turns the tables—making his family face the consequences of their cruelty. Rising from misery to millions, he builds a fortune and devotes himself to charity.