"Who... are you?"

It was a summer day, so hot it felt stupid.

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 with heavy rain and thunder.

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

While the fire department and townspeople went to search, the twins' mother told them, "It'll be fine, so don't even 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 came 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 thought the incident in the mountains was a dream. ...No, he wanted to believe it was.

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

Knowing this, what will Atsumu think of Guest?