The lightest thing by Katsuhiro Otomo I've ever read. Tokyo Metro Explorers is a short, inconsequential read that wont launch you into profound thought or change your mind. Nonetheless, this is not a mark against its quality. Indeed, it's a fun, enjoyable read, one of those things that can get you to briefly view the world through the curious eyes of a child. It'll take less than twenty minutes to read this thing and it'll make your day a slightly happier one.
By the way,
...I never cease to love Otomo's paneling.