This is a very bizarre work that explores the supernatural, mental illness, and the trials of being human. While it is deeply philosophical, it does have some moments where the philosophizing becomes extraneous and unnecessary, but it doesn't take away from the work as a whole.

In summary, the main character, who has suffered from some mental illness as well as a "fall from grace", so to speak, ends up pretty much homeless after living a life of luxury. A eccentric rich person offers him money to have this "trepination" procedure done, theoretically to increase his extra-sensory perception. He then gains the ability to "see" the heart of people--the real human, the summation of their memories, emotions, and experiences. These people become "monsters" to him, though their appearance does seem to abstractly reflect their state of self. How the main character reacts to this seems to evolve and change over time--eventually, it becomes his entire world. This story is as much an exploration of the abstract concepts the author lays out as it is a story about a man falling further into a state of mental illness.

The story is definitely a thinker, and leaves the reader pondering the concepts, symbolism, and even the meaning of some of the events in the story. In the best possible way. The author never really gives an answer to the riddle he illustrates, and at times dosen't quite pin down a real point.

While many people will enjoy this style, others may find it irritating and unsatisfying. The concepts, art, and overall message of the manga are intriguing, and there is enough action and character development to keep the reader interested to find out what's going to happen next.

I recommend this to any manga reader who enjoys the bizarre, philosophical explorations of psychology and human nature.