Fifteen Years to Wait for Migratory Birds

Our hero and heroine meet each other when they are fourteen, and she has had a crush on him for the longest time. However, she does not confess due to her unattractive looks leading to her low self-esteem. And just like, days become months, and months become years. She stays beside him as his best friend for fifteen long years.
~~ Adapted from the novel "Fifteen Years to Wait for Migratory Birds" (十五年等待候鸟) by Ying Feng (盈风).