Past that was Forgotten (忘れ去られた過去 Wasuresara Reta Kako) is the sixth episode of Ultraman Ginga S. This episode marks the first appearance of Hiyori, a Victorian that would join the main cast of the season.
The Victory Lancer is stolen by a strange woman who claims to be a Victorian from a surface. But Queen Kisara and Sho have no knowledge of her. What is her past?
In a vision, Kisara sees a Victorian girl being outcast. While on a patrol with Arisa Sugita, Hikaru spots Sho in the forest and a woman tailing him quietly. Hikaru joins Sho, but the mysterious woman ambushes them and steals the Victory Lancer. She claims she is taking revenge upon the Victorians. She then Monslives into Gomora. Hikaru transforms to engage her, but is beaten. Hiyori hears Shepherdon's cry and suddenly transforms back and teleports away. She returns to Alien Chibu Exceller's Space Base and begs for another chance, before departing with the Gomora Doll once again.
Sho asks Queen Kisara, and she remembers what happened: Long ago, the Victorians lived harmoniously with a child named Hiyori, who played with Shepherdon. But the peace was broken when Victorians declared a civil war over the use of the Victorian stones. Her father/Grandfather was a member of the sect that wished to use the Victorium stones instead of sealing them away and held the Victory Lancer. Hiyori was also good friends with the monster Shepherdon and lived through the conflict that nearly destroyed her people. In the end her father's sect was defeated and though a child, she and her father were cast out of the Underground realm of the Victorians, and sent to the earth. All of her comrades died over the years leaving her as the last living member and causing her to hate the other Victorians, changing her into the vengeful person she is in the present.
Hiyori monslives into Gomora. Ultraman Ginga appears and faces her again. He nearly defeats her, but Shephardon takes the beam in her place. Fire Golza arrives, Monslived by Android One Zero, to assist Hiyori while gaining the upper hand. Hiyori has a change of heart and fires Gomora's Oscillatory Wave at her. Fire Golza then knocks her down, but she is protected by Ginga and Shepherdon. She is defeated but throws the Victory Lancer to Sho. Sho transforms into Victory and he immediately "UITrans" his right arm into EX Red King Knuckle to combat Fire Golza. Victory then charges up the knuckle and destroys Fire Golza with the Ultimate Punch. Android One Zero, however, recovers her Spark Doll and goes back to to Exceller's Base with it.
Afterwards Hiyori meets with Queen Kisara via a hologram and is allowed amnesty for her crimes and those of her tribe, being allowed back into Victorian Civilization. Meanwhile, Exceller finds a great discovery on Shepherdon. End.
- Hikaru Raido (礼堂 ヒカル Raidō Hikaru): Takuya Negishi (根岸 拓哉 Negishi Takuya)
- Sho (ショウ Shou): Kiyotaka Uji (宇治 清高 Uji Kiyotaka)
- Hiyori (ヒヨリ Hiyori): Meiku Harukawa (春川 芽生 Harukawa Meiku)
- Arisa Sugita (杉田 アリサ Sugita Arisa): Yukari Taki (滝 裕可里 Taki Yukari)
- Gouki Matsumoto (松本 ゴウキ Matsumoto Gōki): Takahiro Katou (加藤 貴宏 Katō Takahiro)
- Tomoya Ichijouji (一条寺 友也 Ichijōji Tomoya): Takuya Kusakawa (草川 拓弥 Kusakawa Takuya)
- Yoshiaki Jinno (陣野 義昭 Jinno Yoshiaki): Ryuichi Ohura (大浦 龍宇一 Ōura Ryūｉchi)
- Android One Zero (アンドロイド・ワンゼロ Andoroido Wan Zero): Moga Mogami (最上 もが Mogami Moga)
- Repi (レピ ): Hinata Yamada (山田 日向 Yamada Hinata)
- Sakuya (サクヤ ): Rina Koike (小池 里奈 Koike Rina)
- Kamushin (カムシン ): Yôsuke Saitô (斎藤 洋介 Saitô Yôsuke)
- Queen Kisara (キサラ女王 Kisara Joō): Mirai Yamamoto (山本 未來 Yamamoto Mirai)
- Ultraman Taro (ウルトラマンタロウ Urutoraman Tarō Voice): Hiroya Ishimaru (石丸 博也 Ishimaru Hiroya)
- Alien Chibu Exceller (チブル星人・エクセラー Chiburu Seijin Ekusera Voice): Takuya Eguchi (江口 拓也 Eguchi Takuya)
- Ultraman Ginga S Volume 2 features episodes 4-6
- Ultraman Ginga S Blu-Ray Box I features episodes 1-8.
- This episode was later featured in Ultraman New Generation Chronicle episode 5, "Sorrow! Past that was Forgotten!!".