The Ghost Detective and Who Are You are both similar because they are about ghosts and detectives that deals with supernatural cases..

Right from the beginning they seemed similar, both have the same main plot of time traveling, they're both cute, short and refreshing as well...

While I was watching Montage, I was reminded of Memory by how they both lost there kid in an accident and the heart ache they felt when the statute of limitations was near...
Granted they are different in a lot of things, but both are so heartbreaking...

Both are about a mother trying to save their child from a kidnapper...