Hatori is a wonder because he is him. This chapter is yet another testament to his insane resolve to find fun – emphasis on insane, because he clearly isn't entirely right in his head.
Also, why does Seto just carry around a book of riddles? I wonder what wonders these people have up their sleeves.
Lastly, I hope that this series will retain its slice-of-life-ness to some extent, because the random adventures were awesome.