Sa-yo-na-ra Earth (サ・ヨ・ナ・ラ地球 Sa.Yo.Na.Ra Chikyū) is the 4th episode of Ultraman Tiga.
The military is conducting a test of a new missile, when an unidentified object appears in the sky. It tries and then manages to pierce the area's security. When General Sawai has the officials raise the shielding around the base, they are shocked when the creature manages to override the controls. They manage to drive it away, a piece falling off as it flies back into the sky. Sawai asks who had worked on the new security controls, and is informed that a scientist who used to work there is now on a mission to Jupiter and Saturn.
Over the next few days there were reports that the three space travelers had reappeared to their loved ones, even though no one else had seen them. It is discovered that the piece of the monster that had fallen off is from the spacecraft that the scientist and his companions were on. Analyzing unusual waves coming from the monster, GUTS finds that the scientist had left a video of the last moments of the mission, before an unknown ball of light sucked up the spacecraft and its occupants, remaking them into its new body. It then used their knowledge and emotions to find earth and strategic sites that would aid it in feeding.
There is much consternation about attacking the monster, since members of GUTS feel that there is a way to rescue the space travelers, but research shows this to be impossible. The monster reappears to feed once more, and Daigo turns into Tiga to fight it. Soon the fight is in favor of the monster, as it beats down on Tiga. GUTS decides to send photos of the space travelers and their families, in an effort to encourage the travelers to fight the monster from within. This succeeds, as the monster is weakened, and Tiga is able to destroy it. The travelers then become stars which ascend into space to travel and explore.
- Daigo Madoka (マドカ・ダイゴ Madoka Daigo): Hiroshi Nagano (V6) (長野 博（Ｖ６） Nagano Hiroshi (Bui Shikkusu))
- Rena Yanase (ヤナセ・レナ Yanase Rena): Takami Yoshimoto (吉本 多香美 Yoshimoto Takami)
- Megumi Iruma (イルマ・メグミ Iruma Megumi): Mio Takaki (高樹 澪 Takaki Mio)
- Seiichi Munakata (ムナカタ・セイイチ Munakata Seiichi): Akitoshi Ohtaki (大滝 明利 Ōtaki Akitoshi)
- Masami Horii (ホリイ・マサミ Horii Masami): Yukio Masuda (増田 由紀夫 Masuda Yukio)
- Tetsuo Shinjoh (シンジョウ・テツオ Shinjō Tetsuo): Shigeki Kagemaru (影丸 茂樹 Kagemaru Shigeki)
- Jun Yazumi (ヤズミ・ジュン Yazumi Jyun): Yoichi Furuya (古屋 暢一 Furuya Yōichi)
- Ultraman Tiga (ウルトラマンティガの声 Urutoraman Tiga no Koe): Yuji Machi (真地 勇志 Machi Yuji) (voice)
- Ultraman Tiga Volume 1 Features Episodes 1-4.