Ben

Ben was once a friend of Arim, and is now (presumably) Aria's boyfriend. He appeared in Wolf Sense.

In Wolf Sense
Ben and Arim apparently each paid ten dollars to a witch for a bucket of water which granted wolf smell and hearing to whoever it was poured over. He poured it on Arim and watched as his friend transformed into an Okami before his eyes. When Arim, now Aria, told him he wanted to make the change permanent, he was initially resistant, but changed his mind when Aria kissed him.