I already time travelled past the 14th but I remember it was Blanche in my town Borei. I haven't done it in Tinytree yet, but last year it was Pudge. Both Blanche and Pudge are next door neighbours to my mayor in each town, so they are the first I greet when I log on and probably the villagers I'm closest to. I thought it was cute.
In the past (my towns are never set to irl time) Biskit, Muffy, Sterling and I think Wolfgang have given me chocolate hearts. Even thou I'm pretty friendly with almost all of Moriyo's villagers, I think Sterling has the highest friendship with Kasumi.
In Cutetown I received a Chocolate Heart from Rasher. He's one of my faves so I'm glad it was him. My other town of Sheepish is too new still so no chocolate heart there.