The White Cat's Revenge as Plotted from the Dragon King's Lap, Vol. 4 (manga)

Ruri, racked with guilt over deceiving the kind people of the Dracodom about her true form, sinks into despondency and lies around doing nothing all day-until she hears Nadasha is finally sending its armies to attack...and that Asahi will be taking part in the battle. She convinces Jade to let her go to the battlefield to see for herself, but the person she finds there is nothing like the childhood friend she remembers...