In fact, I don't think Arai cares much about Klonoa now, for he doesn't really have control over the Klonoa series. Klonoa might just be "a character Namco had him design for the company many years ago" to him. Furthermore, we don't know if Ka64 sent the email to the right place...
Argh! No more worries! At least we've known Ariga can get hold of Arai. When the book is released, let's ask Ariga a favor.