Friend Inside the Box (箱の中のともだち Hako no Naka no Tomodachi) is the seventh episode of Ultraman Dyna.
A spaceship is travelling along the cosmos when suddenly two lifeforms manage to escae from it. A third follows them and they crash land on Earth. The pursuer is an Alien Dais. He quickly dispatches of one of the escapees, a baby Gyabish.
That next day, a young girl named Yuka finds the remaining baby Gyabish washed upon a beach. When approached by Ryo, who was visiting the orphanage along with Asuka, Yuka ran away with Gyabish into an empty room. Here, Yuka confesses to the infant kaiju of her loneliness and how her parents had died in a kaiju attack. At that moment, the Alien Dais had located the Gyabish and attempted to shoot it. Asuka and Ryo intervene in the nick of time and manage to knock the alien unconscious after what seemed to be hesitation to shoot at Yuka.
Back at Grandome, the Alien Dais was being held captive by TPC, while Gyabish was being analyzed. Having woken up from the nightmare of an adult Gyabish killing his daughter, Dais teleported to the location of Gyabish and was prepared to kill it. However, Yuka quickly jumped in front of the kaiju, who had now grown larger in size, and managed to buy enough time for Super GUTS to surround the alien. Suddenly, Gyabish vanished along with Yuka.
Back in the command center, Dais explains the true nature of Gyabish of how it ferociously destroys civilizations. Meanwhile, Gyabish continues to grow in size; entering its intermediate stage at first, proceeding to absorb Yuka into its eyes, before growing full size. Super GUTS dispatch with the Alien Dais, and allow him to teleport into the feral monster's eyes to save the young girl. But before they could escape from the vicinity, Gyabish manages to mortally wound the Alien Dais - who managed to save Yuka from the blast at the last moment. Asuka carries the two to safety, but the damage had already been done. Remarking the resemblance between his daughter and Yuka, and wishing for the earthling child to live strong; Alien Dais perishes. Asuka fulfills his dying wish by giving Yuka the pendant worn around Dais' neck.
An enraged Asuka now transforms into Ultraman Dyna in order to kill the brutal monster. Initially, Dyna was outmatched by the feral nature and animalistic strength of Gyabish and was tossed around easily. After being cheered on by Yuka, Dyna managed to cut off Gyabish's tail with the Dyna Slash and fully kill it with the Spacium type Solgent Beam.
The following day, Super GUTS visit the orphanage again; and Asuka teaches Yuka that she should try and make friends in order to live strong like the Alien Dais wanted.
- Shin Asuka (アスカ・シン Asuka Shin): Takeshi Tsuruno (つるの 剛士 Tsuruno Takeshi)
- Gousuke Hibiki (ヒビキ・ゴウスケ Hibiki Gōsuke): Ryo Kinomoto (木之元 亮 Kinomoto Ryō)
- Toshiyuki Kohda (コウダ・トシユキ Kōda Toshiyuki): Toshikazu Fukawa (布川 敏和 Fukawa Toshikazu)
- Ryo Yumimura (ユミムラ・リョウ Yumimura Ryō): Risa Saito (斉藤 りさ Saitō Risa)
- Kouhei Kariya (カリヤ・コウヘイ Kariya Kōhei): Takao Kase (加瀬 尊朗 Kase Takao)
- Tsutomu Nakajima (ナカジマ・ツトム Nakajima Tsutomu): Joe Onodera (小野寺 丈 Onodera Jō)
- Mai Midorikawa (ミドリカワ・マイ Midorikawa Mai): Mariya Yamada (山田 まりや Yamada Mariya)
- Alien Dais (ダイス星人 Daisu Seijin): Seiji Mori (森聖二 Mori Seiji)
- Yuka Yoshimura (吉村由香（ヨシムラ・ユカ Yoshimura Yuka): Mirai Yamashita (山下未来 Yamashita Mirai)
- Narrator (ナレーター Narētā): Yuji Machi (真地 勇志 Machi Yūji)
- Ultraman Dyna
- Flash Type
- Ultraman Dyna Volume 2 features episodes 5-8.