The CEO's Secret Billionaire

A crippled live-in son-in-law is looked down upon by everyone, and even his own wife thinks he's useless. Just as his wife is humiliated by villains and her company is on the brink of collapse, the protagonist's three-year agreement ends. He reclaims his family identity, inherits an immense fortune, helps his wife put the villains in their place, saves the company, and becomes the chairman again. He returns to a happy and blissful married life with his wife.