The Supreme Court has rejected an appeal by actor Manabu Oshio, upholding a lower court-imposed 30-month prison term for giving the synthetic drug Ecstasy to a girlfriend and neglecting to take proper lifesaving actions when she became ill after consuming it.

While Oshio, 33, has the right to file an objection, it is rare for the top court to reverse a decision and he is expected to be imprisoned once the sentence is formally finalized.

Because his offense violated an earlier 18-month suspended prison term for drugs, he will effectively be behind bars for four years. In a statement issued through his lawyers, Oshio said he was not happy with the decision.