It's usually really hard to get Japan domestic awards on weekends even when there isn't a festival--JAL and ANA typically make inventory tight on Friday nights, Saturday mornings and Sundays, probably anticipating (correctly) that commuters and weekenders will be packing the planes at these times.

HND-CTS, by the way, is the busiest airport pairing in the world by passengers, at least last time I looked up the numbers (though I think NYC-MIA/FLL may be a busier city pairing, diluted by the fact that there are multiple airports at each end). Makes sense given the score and a half of heavies that fly the route in each direction every day.