Gekkou (ゲッコウ?) was a student of Yabakune High School (矢場久根高校?) who was planning to become Yabakune's new leader in her third year, replacing the previous leader, who had lost Yabakune to Gekioko Koko. She went to Majijo with some subordinates, to introduce themselves to Salt's successor Sakura. Gekkou would later be one of Yabakune's Generals under Head, who became the new leader instead of her.
Majisuka Gakuen 4
After finding out about the Rappapa President's absence, Gekkou brought her faction to Majisuka Jyogakuen. They intended to introduce themselves to the presumed successor of Rappapa, Sakura. As they entered the lobby, they brought down a gang who were preparing graduation decorations at the time. After testing Sakura's capabilities, Gekkou silently left with her gang.
Majisuka Gakuen 5
After Salt rescued Antonio from the Ryuto Clan, the Kango-ka President declared another truce between Gekioko and Majijo. Yabakune did not take the news of the peace treaty well. Gekkou became one of the Generals under Yabakune's new leader Head, along with her former subordinate Kaibun. The leaders of Yabakune invited Kango-ka's President for a meeting on their school's grounds. Due to Antonio's injuries, the vice president Coby led the Kango-ka members to the meeting. As Yabakune "asked" for a reconsideration of the treaty the meeting became a heated argument between the two schools. It soon turned into a fight between the two sides, with Gekkou facing Coby.
After Salt's death, Gekkou and Kaibun gathered a group and went to Majijo with the intent of facing Sakura. They instead met Yoga of Rappapa's Four Heavenly Queens, who was wandering around the school's bike garage. The group led by Gekkou attacked the Queen relentlessly, but Magic arrived to assist her Yoga. Yabakune's side was unable to defeat Yoga or Magic, despite an advantage in numbers.
As Yabakune attempted to hunt down the Majijo students, Amon confronts Snake about why they had not yet attacked Rappapa. Head stated that the fight with Rappapa would come soon since since Majijo was in chaos. Suddenly, the New Rappapa members arrived to the place where the best Yabakune fighters were meeting. The younger generation of Rappapa challenged Yabakune to stop their hunt, but were overwhelmed by the opposition. Gekkou fought and beat down both Katabutsu and Jisedai.
Yabakune were challenged to a rematch by the New Rappapa members, who this time had along their new president and strongest fighter Katsuzetsu. Seeing the new president, Gekkou attempted to fight Katsuzetsu, but the other girl dodged every blow the Yabakune general made. As the fight continued, Gekkou again fought Jisedai, but this time she was defeated.
Days after their defeat, Candy and Rookie returned to Yabakune. They reported that they were kidnapped by some Mafia goons but were saved by Yoga. Angry that they were helped by a Rappapa queen, Gekkou beat the two up. Head was infuriated and slammed Gekkou in a wall, since she acknowledged that they Yabakune now had a debt of gratitude to Majijo.
Gekkou and the rest of Yabakune's higher ups went to Majijo to escort Candy and Rookie. The duo apologized to Rappapa for not being able to help Yoga. Head allowed Peace to release her anger about Yoga's fate by beating up Candy and Rookie. Yabakune offered their condolences and left Majijo without making a truce.
Yabakune watched the movements of Majijo and Gekioko, and decided to join the two schools as they charged into the Mafia meeting. Gekkou pointed out that her school couldn't let the others have all the fun. The top members of the Yabakune, Majijo, and Gekioko walked side-by-side towards the appointed meeting place.
Yabakune followed Majijo to the Chitoitsu's assigned exchange location, and witnessed the Mafia shooting down Magic. Enraged when they attempted to shoot Otabe, the whole Yankee Alliance began attacking the attendees of the meeting with weapons. Gekkou ran out of ammunition, but managed to get her hands on a shotgun. When her new gun also ran out of bullets, she used it as a baton and still charged at the enemies. Gekkou was soon shot down alongside the rest of the Yabakune and Gekioko students.
Majisuka Gakuen 5 Gaiden
- Gekkou's name could have been derived from either the Japanese word for "moonlight" (月光 gekkou?) or from "gecko" (ゲッコウ gekkou?).
- Nagao Mariya is the only member who appeared in almost all of the canon seasons of Majisuka Gakuen, including the Musical Stage. The only series she did not appear was Majisuka Gakuen 0, which was a production exclusive to HKT48.