The core concept was appealing, and in the end, it was not a terrible watch.

First, the flaws.
(a)I'm guessing the Drama's source is a manga of some sort, because the lead male character was totally flat. It's as if he LOST a dimension when moving from paper to screen. Only in the very final scene, as the credits are starting, do we see ANY character growth at all.
(b) Every episode's story was effectively EXACTLY the same. Just as well there were only three, because it was very definitely, "seen one, seen 'em all"

Now, the saving grace

The female lead was not only super-kawaii, she super smart. SHE was the brains of the outfit and the show made sure this was VERY obvious. "Cute smart girl makes moron male cop look good" is not a formula that would even be imagined in Korea, where it seems that it is forbidden by law for the word "genius" to be used of a female lead (unless the male lead is a "super genius")

Also, I felt that for a very young actor, Ms Himabe did very well with the role. HER character was given some depth, we definitely saw both good and less-good sides of her personality, and of course, she was unapologetically the heroine and star.

For that refreshingly pro-female POV , and for the fun of watching a smart, cute female lead, this Drama scraped into the pass range.