Arrogant ace striker Kian and cold reserve player Milo become step-brothers. To stop their parents' wedding, Kian forces Milo to sign a 'dangerous contract': pretend lovers to ruin the engagement. Kian 'coaches' Milo. When Milo shows interest in another, Kian gets jealous, loses control, and takes him by force. The act turns real. Kian's arrogance masks his craving for love; Milo is his soulmate. After a winning goal, Kian proposes with a black diamond ring, making the contract eternal.