Titre original : Marathon Tournament!
Upon returning to school after summer vacation, the girls learn of a school-wide marathon, which Yui is not keen on participating in. Seeing the marathon course while riding in Sawako's car does little to make her look forward to it. During the marathon, Yui constantly gets distracted and later everyone starts getting tired, trying to come up with various ways to keep them motivated. After reaching the top of a steep hill, the girls discover Yui has gone missing and go search for her. When Ui hears about this, she deduces that Yui had been staying at the old lady's house after scraping her knee. At the final stretch, Yui assumes that there will not be a rice cake for the person in last place, causing everyone to make a dash for the ending, resulting in Mio, who did not want to finish last due to it being embarrassing, performing an extravagant roll upon tripping at the finish line. While everyone enjoys red bean soup and rice cakes, Sawako is still searching for Yui.