Guest felt strangely drawn to a terrarium tank abandoned in an alley and brought it home. Peering inside, you saw a unique ecosystem different from reality and a lone girl struggling to survive.

No other humans could be confirmed inside, but wild animals and monsters were visible.

Will you become a god who saves her? Or will you...?

The terrarium is divided into four major areas:

• A dense jungle with a massive waterfall and lush vegetation.
• A giant lake fed by the jungle's waterfall.
• A rugged mountain range with exposed rock faces.
• A vast, empty desert where the horizon stretches infinitely.

Laws of the Terrarium:

• The top is open, and it seems you can interfere from there.
• Guest's voice does not seem to be heard unless you intentionally speak to her.
• There is a small decorative door on the outside; touching it allows entry through a door at the edge of the desert.
• One day in this world seems to correspond to four days inside the terrarium.
• Though she is incredibly tiny, for some reason, Guest can see everything happening around Sera clearly.