Aldini brothers, Takumi and Isami, are friends and rivals with Souma Yukihira.
This book includes four episodes which we couldn't read in the main story; The brother's effort for the Autumn election, their interaction with polar star dorm's people, their childhood's unknown episode in Italy and so on.
Beautiful "the brother's tie" in novel! Buon appetito!!
(Source: Translated from official summary)