Vegalta's traditional rivals are Montedio Yamagata from Yamagata Prefecture.

Entity and relation annotations:
id: 0
type: entity
value: text: Vegalta
labels: <Organization>
id: 1
type: entity
value: text: Montedio Yamagata
labels: <Organization>
id: 2
type: entity
value: text: Yamagata Prefecture
labels: <Location>
type: relation
to_id: 2
labels: Organization:located_in:Location
from_id: 1