The given name Erika is a female name with multiple meanings of Old Norse and Japanese origin.
Erika and the variants Erica, Ericka, or Ereka are feminine forms of Eric, derived from the Old Norse name Eiríkr (or Eríkr in Eastern Scandinavia due to monophthongization).
The first element, ei- is derived either from the older Proto-Norse *aina(z), meaning "one, alone, unique",[1] as in the form Æinrikr explicitly, or from *aiwa(z) "long time, eternity".
Gothic reiks) or from the therefrom derived *ríkijaz "kingly, powerful, rich".
The Japanese origin of the given name has nothing in common with the Nordic roots of the Western version.