The 89th Suggestion: And There Is Only One Rule (そしてルールはただ一つ, Soshite Rūru wa Tada Hitotsu) is the eighty-ninth chapter of the series Medaka Box.
Summary[]
On August twenty-second, the Student Council and Class -13 gather for the final battle. Questioned by Naze, Zenkichi tells her about Shiranui. Choujabaru tells Shiranui to select a card, but is refused. Shiranui declares that Kumagawa will represent Class -13. Koga is shocked, and tries to argue against it. Zenkichi is grudgingly amused by the depths of Shiranui's machinations. As Choujabaru protests, Shiranui reveals she has received authority from his superior Tachiarai, explaining she spent the past month winning over the Election Management Committee chairwoman. Choujabaru is forced to concede. Zenkichi tells Naze that Shiranui is the type who just changes the rules to suit her needs. Medaka and Kumagawa both agree to Shiranui's terms. As Shiranui moves out of the way, she and Zenkichi share a smile. Choujabaru asks Kumagawa to pick a card. Kumagawa selects the Human card. Naze thinks to herself that there were no surviving records of a President's Battle. Choujabaru explains that the Human card allows for the current president to choose the rules. Medaka ordains the entirety of the academy grounds as the field, no time limit, and that the loser is only so if they believe they have lost. She offers her hand to Kumagawa, who uses the chance to attack her. Medaka blocks his attack and grins, stating she feels as though she has been waiting three hundred million years for this day.