Even Dragons Have to Give It a Try

The protagonist transmigrates to another world and picks up a dragon. Each thinks they've taken in a pet. The human earns money to raise the dragon, while the dragon robs people to support the human. Later, after they fall in love, the human gazes solemnly at the dragon. "You have to be on the bottom." The dragon asks, "Why?" The human replies, "I'm afraid you'll stab me to death." Theme: .