Hallie and Andrew met just a few days ago, but they share a special bond on this Valentine's Day.
"You're my valentine," the two said to each other.
Both are only 7-years-old and suffer from the same mysterious illness - one that only affects a handful of people in the world. They get daily fevers and have experienced numerous strokes in the same area of their brains.
Hallie's already survived seven strokes; she experienced her first stroke as a baby. Andrew has survived five strokes and struggles with paralysis.
"It's really nice. They have each other," Andrew's mom, Paula Schmitz. said.
Matching craniotomy scars are a testament to their shared painful past.
"It's just beautiful...," added Hallie's mom, Evan Luton. "...they're amazing little people."
This week, they're staying at the Children's Inn and participating in genome sequencing at the National Institutes of Health. Researchers are looking for a similar mutation to explain their recurrent strokes; they hope to find a treatment.
With candy and small gifts, they celebrated Valentine's Day together.
They've both suffered so much already, and on this holiday, they can teach many others about hope, joy and the gift of love and friendship.