Ren has a red lunch box.

He likes it very much.

His mother made rice balls and eggs today.

At lunch time, Ren opens his bag.

The lunch box is not there.

"Oh no," Ren says.

Mika sits next to him.

"What is wrong?" she asks.

"My lunch box is gone."

Mika looks under the desk.

Ren looks in his bag again.

They look near the window.

Then Mika sees a red box on the teacher's desk.

"Is that yours?" she asks.

Ren looks at it and smiles.

"Yes, it is mine."

The teacher says, "You left it at the door this morning."

Ren takes the lunch box.

"Thank you," he says.

Mika smiles too.

"Now you can eat."

Ren opens the box.

The rice balls look small and warm.

He gives one to Mika.

"For helping me," he says.

Mika laughs.

"Thank you. This is a good lunch."

Ren nods.

A lost lunch box becomes a happy lunch.