Haru no Noroi (2021)

They have a similar plot of their sibling' love interest approach them after a tragic incident. In the case of Haru no Noroi, the FL is approached by her dead sister's fiance' but in Kiken na Venus, the FL is asked for help by his missing brother's wife. People who like mystery should definitely watch Kiken

Both are serious jdoramas with darker undertones. The plots aren't that similar but family relations do play a big part in both. Well, both are good jdoramas that I recommend if you liked either of these.