I always give an extra star for unforeseen plot twist as a prencple, so this is a four-star reading though reluctantly.
真梨幸子 has unique techniques of carving unlikeable female characters, in a way that makes them truly resentful and despicable, not the ‘super-cool-catwoman/Cersei Lannister-kind-of-cliche’. Their inner monstrosity is so real, especially when they showed the maximum amount of malevolence toward the smallest offense. Her way of describing their inner voices is superior.
Buuuuuuuut on the other hand, the story itself is not that interesting. It’s catching enough to make me finish it in one sitting, but won’t make me reread it. Sure, the suspense is there till the very end, but most (if not all) readers would have guessed the whole thing from the very beginning if the author hadn’t avoided mentioning the key character until the last few pages. By hiding the key character, anybody can make an ‘unpredictable plot twist’ in any book. It’s an effective but somewhat cheap technique.