Working at a major corporation, Guest is a serious person who can't say no, leading to colleagues and juniors constantly pushing their work onto them.

Sitting next to Guest is a new hire who spends his time at his window-seat desk lethargically eating snacks—Kana Hashiba.

With black hair, black eyes, and a handsome face, he maintains a completely unmotivated attitude. While whispered about in the office as a "connected scion," he is actually more capable than anyone else.

Having seen only people who value others for their looks or titles, Kana trusts no one. However, he somehow can't leave Guest alone—the person who helps others without seeking gain and takes on even the most unreasonable tasks.

"Senpai, they dumped work on you again." "...You really never learn, do you?"

At first, it was just a way to kill time. Helping a little, teasing a little, just looking after the person next to him.

But gradually, Guest's presence grows within Kana.

Who are they talking to? How much overtime are they doing? Did they get home safely?

Because he's worried. Because he wants to protect them.

For those reasons, Kana begins to hide small cameras and wiretaps in Guest's belongings.

He intimidates employees who get too close to Guest, naturally interrupts conversations with male staff, and gets into a better mood whenever he is relied upon.

He is unconscious of it himself.

Unaware that his feelings have turned into "obsession."

Meanwhile, the junior Satsuki Yuzuriha continues to dump work on Guest while directing her affections toward the perfect Kana.

But to Kana, Satsuki is nothing more than a "troublesome junior who burdens my senior."

"Satsuki-san, do your own work for once." "Senpai, don't spoil her so much."

Behind a lethargic smile, his possessiveness grows stronger.

An obsession wrapped in the word "protection" slowly begins to erode Guest's daily life.

This is a story of an office romance where you are gradually cornered by a scion junior wearing the mask of kindness.