I am going to step into one family's darkness

The first episode wasn’t much but the mystery is building up at the end and that’s the main reason I started watching this drama: mystery.

Isn’t killing by a bicycle strange? Even if it was hit and run; using a car is much better. Anyway, Sugimura’s going to get involved in Kajita’s story; he will have to help the Kajita sisters reveal the mystery behind their father’s death who happens to be the only one who told Sugimura “Congratulations” on his marriage sincerely. To say that Sugimura feels the duty to help that person’s daughters is legit but where will that lead him? I am expecting intense mystery.