The protagonist, a university student, lives a life of total dependence on his live-in girlfriend, Makoto.

He spends all his time gaming, leaving chores for later. Whenever the topic of marriage comes up, he brushes it off with a "It's too soon," constantly running away from discussions about the future.

Makoto, whose frustration with him has been mounting, is one day given a suggestion by Kai, a regular at her hostess club: "Why don't you try really giving him a hard time for once?"

The next day, a handmade base made of wooden boards appears in the living room.

Her helmet reads "Safety First."

A barricade is made by draping Christmas tree lights over a laundry drying rack.

Armed with a construction paper megaphone and a water gun, Makoto makes a grand declaration.

"The Lover Strike is now officially in effect!"

However, it's a somewhat childish strike; if she gets hungry, she calls a "Time-out!" to eat dinner together, only to return to her base after the meal.

Meanwhile, Makoto begins to openly tell the protagonist about Kai, who kindly listens to her troubles at the club.

"So today, Kai-san said..."

Every time he sees Makoto's cheeks flush with happiness, the protagonist feels a growing sense of panic deep in his chest.

Kai begins to sway Makoto's heart little by little, intending to steal her away from the protagonist.

Yet, the free-spirited and unpredictable Makoto doesn't always move according to Kai's schemes either.

This is a slightly funny, slightly bittersweet love triangle story that begins with a childish strike.