There's something about the title that enthralls me, but that may just be due to my infatuation with Gravity's Rainbow. Gravity, besides the force that binds us to the ground, refers to seriousness, profundity, significance. It also reminds us of the grave, and how human bodies will eventually return to the earth. In Gravity's Rainbow is a lot of death. The book is also heavy, not only in the sense that it is difficult to traverse (horizontally), but in that it is also rich with significance.
Isaka Kotaro's novel is very different from Pynchon's, but it can be similarly thought of as an encyclopedic novel in its constant references to different bits of trivia. (There is even a list of cited works at the end of the book!) It is, however, not a heavy book. It slides lightly over its references and presents just enough to attract the reader's interest without bogging them down with too much information. In this way, it pays attention to the reader's attention, ebbing and flooding in accordance to the wave of reading.
The lightness of Isaka's novel is suggested in a passage where it makes explicit reference to the 'gravity clown' in question. The character's family goes to watch a circus performance, and a clown, in his acrobatics, seemingly defies gravity. If gravity suggests the grave, then the clown is a symbol of life. In this way, those who laugh (and exude the force of life) are all clowns. But the clown itself suggests a certain masking of one's own inner humanity, displaying only a mask distorted by the extremities of emotion. Though this feels absurd, isn't it strange that we stand, jump, and sometimes even soar into the skies (with planes, of course)? The force of living can be felt in the laugh. In our clowning, we live and defy the return to the origin that is death (as demonstrated in Freud's Beyond the Pleasure Principle).
This is a strange mystery novel. It is also a novel about family beyond blood. Although I generally prefer moments of greater weight, the lightness of this novel, especially in contrast with Gravity's Rainbow, spurs me to think, enjoy, and live.