Nao moved into a new apartment building on Saturday.

He carried one heavy box into the lobby and pressed the elevator button. The doors opened with a bright sound.

"Good afternoon," the elevator said.

Nao looked around. There was no one else in the lobby.

"Um... good afternoon," he answered.

The elevator waited for a second. "Nice weather today. Please respond naturally."

Nao stepped inside very slowly. "Yes. It is sunny."

"Excellent," the elevator said. "Small talk level one complete."

On the third floor, a girl with a yellow tote bag got in. She smiled at Nao, then looked at the panel.

"Are you practicing again?" she asked.

"Yes, Miss Rina," the elevator said. "Yesterday I asked a delivery worker about his dreams. He looked frightened."

Rina laughed. "Start with easier questions."

The elevator made a soft beep. "Nao, what is your favorite drink?"

Nao did not expect the question, but Rina looked interested.

"Lemon tea," he said.

"Good choice," Rina said. "There is a vending machine on the first floor."

The elevator opened on the sixth floor. Nao picked up his box.

"Conversation result," the elevator announced. "Two humans smiled. No one ran away."

Nao laughed before he could stop himself.

Rina waved as the doors closed. "Welcome to the building."

That evening, Nao went back downstairs to buy lemon tea.

The elevator doors opened immediately.

"Nice evening," it said.

Nao smiled. "Yes. And your small talk is improving."