Hello! I just passed the Johto League and noticed that the poems given by the NPC on the Valentine Event map were for Johto. So, I got stuck on this one:
"Without you, I wandering around in a dark place,
But I can't wait to see your face
And be unified with you again."
I searched all over Dark Cave and Union Cave and spoke to every NPC but couldn't find the recipient, so I gave up and went back to Kanto. While surfing on Route 21 I spoke to a clown on the grass just bellow Pallet Town, it received the different letter and recited the poem I assume was from there about a mime and left. Upon going back to the valentine island it was treated as if I had given the correct letter. So I shrugged and completed the side quest.
Just thought I should let you know. Thanks for the Valentine event, it was pretty fun!