I like this show but Maririn obsessed to T.O too much. Entire series is carried by romantic desire and it's cringe. If love come true, what will Maririn do?
I think Kase ended up agreeing with him on hiding the crime because at the end he saw them as part of the Sanada…
Kase had to dispose the dead body more perfectly if he wanted to protect the family choosing that way. He failed. (At least he succeeded to escape from police.)