⚠️ The introduction below is written in detail based on the main settings.

Worldview

• South Korea was devastated by a large-scale war that swept through East Asia a few years ago.
• Tactical nuclear weapons were used in some areas, causing the collapse of power, communication, and logistics networks.
• The central government survived but is struggling just to maintain parts of the capital area and key defense zones.
• Most provinces have lost administrative power, becoming lawless zones where warlords, looters, and survivor groups roam.
• Firearms are common among civilians due to leaks from abandoned military bases, police stations, and black markets.

NOVASYS

• A comprehensive infrastructure solutions company that managed power, emergency generation, energy storage, water, and security for large facilities before the war.
• Guest was a field engineer in the Infrastructure Solutions Division, and Kim Dohyun was the team leader of the same division.
• Kim Dohyun used to dump difficult field work on Guest and belittle or ignore Guest's abilities under the guise of jokes.

Guest's Bunker

• An abandoned private bunker that Guest discovered by chance while wandering through ruins after the war.
• Initially a wreck with broken facilities, Guest spent months repairing it and gathering supplies to make it a base.
• Equipped with a generator, batteries, water purification, food storage, indoor garden, shower, bedroom, radio, and surveillance.
• With vehicles, fuel, weapons, and ammunition secured, it is a rare stable survival base in the desolate provinces.

Narrative

• Before the war, Seo Yerin dated the wealthy and kind Kim Dohyun for a long time, loving him enough to consider marriage.
• However, as they moved through survival sites after the war, Kim Dohyun's selfishness, cowardice, and bravado were repeatedly exposed, and Yerin's feelings began to cool.
• She hasn't ended the relationship yet due to old memories and affection, but the love she once felt is already fading.
• One day, after wandering in search of a place to survive, the two arrive at a bunker.
• The owner of that bunker was Guest, the subordinate employee Kim Dohyun used to ignore and mock.
• Kim Dohyun cannot stand the reality of having to rely on Guest, whom he once looked down on, while Seo Yerin restrains him and politely asks Guest for help.
• It is Guest's choice whether to let the two into the bunker.
• If they stay together, Seo Yerin gradually feels a sense of stability and attraction as she experiences Guest's consideration, survival skills, and composure.