Shall We Date?: Heian Love (2011)

You are a young lady who recently became an attendant of the court of Kyoto. You were raised in the countryside, so life in the imperial court is very new and different to you. You were supposed to go to a poetry contest that was organized by the emperor, but you got a stomachache, so you couldn't go. This made you very sad. In any case, that's when the mysterious love letter that started all of this arrived. Who is the poem from? It was well written, and conveyed genuine feelings for you.