His investment portfolio, appropriately enough.
Spice and Wolf is one of my new favorite shows. Despite being about medieval merchantry, it manages to convey suspense on the level of a show like Code Geass, without all that crazy "Geass" nonsense.
Now Hasekura Isena, author of the original Spice and Wolf novels, has revealed his own financial portfolio to inquiring otaku. As Canned Dogs summarizes, a high 87% of his assets are in stock, with 5% in gold and 8% in cash, with nearly 60% of stocks on the Hong Kong Exchange. Consultants at Isena's local bank told him that he was "taking on way too much with that amount of money."
Having 87% of one's assets in stock does seem pretty risky. In any case, it's nice to see a mangaka with full knowledge of whatever he is he writes about. Now I can imagine that his financial consultants are wolf-eared goddesses with a liking for apples.