In the town of Saima, when summer is about to begin, a group of six high school students intend to live a secret adventure by spending seven carefree days in a ruined mining facility.

• Ajiado
• Kyoko Yoshine
• Takumi Kitamura
• Haruka Michii
• Makoto Koichi
• Megumi Han
• Rie Miyazawa
• Takahiro Sakurai
• Takeo Otsuka