Based on a novel by mystery writer Keigo Higashino, Ryūsei no Kizuna tells the story of three orphans, whose parents were murdered long ago. Together, the three vowed on a shooting star to one day avenge their parents. After many years, the two brothers have found the murderers, and are set to carry out their plan for vengeance when they realize they've made a serious miscalculation; you see, their sister...