My Golden Finger Just Wants to Eat Cake

"Klein, do you want to eat cake today?" "We are practicing." "Do you want to eat after practicing?" "Eat." —— Good news: He is dressed as the eldest son of the Viscount family. Bad news: This body has been in a state of confusion for sixteen years, and the title has long been given to his younger brother. Worse news: If he fails the college's assessment within three months, he will have to leave, and he can't read a single word. The worst news: His golden finger only wants to eat cake.