Kiken na Venus (2020)

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

If you love Kiken na Venus..you will also love Yokoso wagaya e

Similarities
Everyone in family has their own secret

Different
Kiken na venus - Family fight over inheritance
Yokoso wagaya e - Family fight against stalker
#recommendations

ML collaborates with missing/dead younger brother's romantic partner. In "Kiken.." he partners up to find his missing half brother.