This ten part Japanese series opens in 2006. Rio is living in a rural area with her father and younger half-brother, Yu. Yu has a condition which means he suffers from amnesia if he gets overly stressed but one day it is Rio who wakes with no memory of what happened the night before... the same night a boy who we saw visiting her home has disappeared. Shortly afterwards events lead to her moving to her mother's in Tokyo. Here she goes to university and joins her mother's company where she is determined to find a cure for her brother's condition. By 2021 she has risen to be the CEO of the company and is close to finding that cure. However things get complicated for her when the father of the missing boy confronts her... shortly afterwards he is murdered leaving her as one of the suspects. Things are further complicated by the fact that the policeman investigating the case is Daiki Miyazaki, a friend of Rio's who she hadn't seen since moving to Tokyo. There are also internal company politics to deal with.
I thought this was an enjoyable series. It effectively set up a mystery and gradually answered various questions and putting forward suspects for more than one crime, I liked to main characters, especially Rio and Daiki and Kase, Rio's lawyer who is somewhat a father figure for her. The mystery elements kept me interested from start to finish. Locations used are impressive; especially Rio's rural home... it could have been selected by the Japanese tourist board it is so beautiful. The cast does a fine job; this includes both those playing our protagonists and those playing more unlikeable characters. By the end there were some good twists and turns; some providing a real surprise. Overall I'd certainly recommend this to fans of Japanese drama series.
These comments are based on watching the series in Japanese with English subtitles.