5 8 3 ▁series ▁electric ▁multiple ▁units . ▁ ▁From ▁ 1 5 ▁November ▁ 1 9 8 2 , ▁with ▁the ▁opening ▁of ▁the ▁T ō h oku ▁Sh ink ansen ▁to ▁, ▁the ▁H ats uk ari ▁service ▁was ▁trunc ated ▁to ▁operate ▁between ▁Mor i oka ▁and ▁A om ori . ▁This ▁was ▁extended ▁to ▁operate ▁to ▁ ▁in ▁H ok ka ido ▁from ▁ 1 3 ▁March ▁ 1 9 8 8 , ▁following ▁the ▁opening ▁of ▁the ▁under se a ▁Se ikan ▁T unnel . ▁The ▁maximum ▁speed ▁was ▁raised ▁to ▁ ▁through ▁the ▁Se ikan ▁T unnel ▁from ▁ 1 6 ▁March ▁ 1 9 9 1 . ▁ ▁New ▁E 7 5 1 ▁series ▁electric ▁multiple ▁units ▁were ▁introduced ▁from ▁ 1 8 ▁March ▁ 2 0 0 0 , ▁with ▁the ▁trains ▁running ▁as ▁Mor i oka ▁– ▁A om ori ▁Super ▁H ats uk ari ▁alongside ▁the ▁Mor i oka ▁– ▁H ak od ate ▁H ats uk ari ▁services ▁using ▁ 4 8 5 - 3 0 0 0 ▁series ▁EM Us . ▁ ▁The ▁Super ▁H ats uk ari ▁and ▁H ats uk ari ▁services ▁were ▁dis cont in ued ▁from ▁the ▁start ▁of ▁the ▁re vised ▁tim et able ▁on ▁ 1 ▁December ▁ 2 0 0 2 , ▁with ▁the ▁opening ▁of ▁the ▁T ō h oku ▁Sh ink ansen ▁extension ▁to ▁, ▁and ▁were ▁su pers eded ▁by ▁new ▁H ak uch ō ▁and ▁Super ▁H ak uch ō