최고의 킬러 `블러드 발렌타인` 그 정체는 수수께끼에 싸여있지만, `랠프`라는 인물을 통해 블러드 발렌타인에게 살인을 의뢰하면 반드시 성공한다는 소문이 돈다. 블러드 발렌타인의 정체는 `크리스트`. 남편이 자신의 정체를 알게 된 뒤, 임신한 크리스트를 버리고 떠난 후 홀로 딸 `린`을 낳아 키운다. 그러던 어느 날 임무를 완수하던 중 고아가 된 여자아이 `코르자이`를 린이 같이 집에 데려가자고 해서 코르자이 역시 딸처럼 키운다. 어느덧 10여년이 흘러, 코르자이와 린은 십 대가 되었고 크리스트는 여전히 블러드 발렌타인으로 최고의 킬러라는 명성을 유지하고 있다. 하지만 어느 날, 린이 학교에서 `선`이라는 남자아이를 짝사랑하게 되면서 린과 크리스트의 평정심이 흔들리고, 급기야 임무에서 실수를 하게 된다. 급기야 크리스트는 선이 임무에 방해가 된다고 판단, 선을 린 몰래 처리할 계획을 세우게 되는데...

2. Mother, child, killer code "Blood Valentine". Everything is going well until the daughter loves to want to break the rules. But the mother's order is "Absolutely do not have a boyfriend." Otherwise, that man will be made to disappear immediately. When the mother and daughter go wrong, Blood Valentine's important work goes wrong, causing both to be hunted by the killer organization. Adjustment of understanding on the heap of blood arises.

2 แม่ลูกรหัสนักฆ่า “Blood Valentine” ทุกอย่างกำลังไปได้ดีจนกระทั่งลูกสาวเกิดความรักจนอยากฉีกกฎ แต่คำสั่งของแม่คือ “ห้ามมีแฟนเด็ดขาด” ไม่งั้นผู้ชายคนนั้นจะถูกทำให้หายไปทันที เมื่อแม่ลูกผิดใจกันงานชิ้นสำคัญของ Blood Valentine เลยผิดพลาดจนทำให้ทั้งคู่ถูกตามล่าจากองค์กรนักฆ่า การปรับความเข้าใจบนกองเลือดจึงเกิดขึ้น