Quick answer — Rei Nakashima performed 1 anime theme, including "GA-TAN GO-TON" from Train to the End of the World.
Rei Nakashima performed the anime theme songs "GA-TAN GO-TON" (Train to the End of the World).
Rei Nakashima's first listed anime theme is "GA-TAN GO-TON", the opening of Train to the End of the World.