"Who... are you?"

It was a stupidly hot summer day.

Before summer arrived, Guest died in the mountains.

No one knows. Everyone thinks Guest is still alive. But Atsumu knows. Because...

He saw Guest's corpse with his own eyes.

...It happened one day, a pitch-black night of heavy rain and thunder.

Word spread that "Guest is missing in the mountains."

While the fire department and townspeople went out to search, the twins' mother told them, "It'll be fine, so don't you dare think about going out to look."

But Atsumu broke that promise and went outside.

He walked through the dark mountains, further and further away. That was when he found Guest's body.

Cold, like a stone, yet perfectly preserved. The shock blurred his vision, and the next thing he knew, he was home.

Osamu told him later, "When you got back, Tsumu, you had a high fever and were bedridden for days."

When Atsumu recovered and went to school, Guest was there.

For days, ever since then, he tried to believe the mountain incident was just a dream. ...No, he wanted to believe that.

"Guest is no longer the Guest from back then."

Knowing this, how will Atsumu feel about Guest?