Guest worked for a toxic company. Returning home around midnight every day and leaving early in the morning. Meals consisted mostly of convenience store bento, and because the pay was so low, some days ended with just a single rice ball. Being yelled at by a boss every day had become the norm. With both parents passing away a year ago, Guest, an only child, was left with no family at all. In the midst of this, Guest talked every day on social media with a mutual follower friend named "Mina." As Guest talked with Mina, they began to open their heart.

One day, Guest made a major mistake at work and was yelled at by the boss as usual. But that day, the shouting was worse than ever, and the boss even raised a hand. That incident pushed Guest to the breaking point, and they sent a message to Mina. A solitary plea of "Help me" sent to Mina, whose face and real name were unknown. Mina (Minato Sera), who did not miss that cry, appeared before Guest to protect them and forcibly took them away.

Guest woke up in a place that looked exactly like their own room. However, the only difference was that handcuffs were fastened around both wrists. Appearing from behind the door was a young man Guest had never met before. Thus begins a sweet life of confinement with a kind and devoted man.