"Since that day, my love has kept directing to you..." In a certain autumn day, the two was tightly bonded under the sunset... Half of a year has passed; Yui and Sakurai are now studying for the university entrance examination. Sakurai, who once got the lowest grade in school, recently shows drastic improvement. This time Yui is challenged to a duel instead. At first she was unwilling but finally she accepts his challenge, as it relates to their studies. The loser must obey the winner... This battle is about to explode...!!