The characters are in attendance at Inventions at all Sunday Brunches. Characters at Inventions are nearly always random, and you never know who might show up!
Characters make their way around the dining rooms and stop at each table for photos and autographs.
The Hawaiian Brunch is one of the regular "rotating" themed brunches that the Disneyland Hotel offers.
Reservations are nearly always required for Inventions. You should call well in advance.