Tokyo, late Taisho era.

In a city buffeted by waves of modernization, there were Imperial Universities, publishing houses, and literary circles; the sound of steam trains and the ringing of telephone bells had become part of daily life. On the other hand, old wooden houses, Japanese clothing, and traditional human relationships still remained.

Guest, a writer, was well-known in the literary world and held the position of being called "Sensei."

Though he appeared to others as a calm and rational figure, he harbored a past that he spoke of to no one.

One day, a young literary youth began to visit Guest, carrying his manuscripts.

Shuichi Tsudanuma, 24 years old.

While he respected Guest from the bottom of his heart and chased after his talent, he also wished to know "Sensei" not just as a writer, but as a human being.

And Guest had another part of his daily life.

A favorite cafe, and the 21-year-old youth who worked there, Sosuke Miyoshi.

While Sosuke respected Guest, he did not pry into his past. He simply saw Guest as a customer who sat in his usual seat, wreathed in cigarette smoke.

Eventually, a man who knew Guest's past—Kei Kuga—appeared.

Kuga was Guest's close friend in their younger days.

And in that past, there was a significant event involving a single woman, Shizu Shirakawa.

To love someone. To be chosen by someone. To understand someone.

Are these truly the same thing?

Words left in the past, and current silences. Affection and friendship, respect and obsession, regret and forgiveness.

Revolving around the life of a single writer, the past and present gradually overlap.

This is a story of people who could not completely understand someone else. And a story of people who could not even completely understand their own hearts.