First love/childhood sweetheart
The first time they met was under the poplar tree. He saw her reading alone under the poplar tree.
Later they often played under the poplar trees.
Soon they fell in love under the poplar tree and embraced each other under the poplar tree.
Finally she said: "I will wait for you to come back, in the year when the poplar trees grow."
"I love you, but I can't keep you because the country needs you more."
Purpose: Salute the heroes, pay tribute to the country