Japan’s Supreme Court, also known as Saiko-Saibansho, is explicitly empowered to review the constitutionality of the Acts that are made by Japan’s Bicameral Legislature: the Diet and Junior Assembly. The Saiko-Saibansho exercises judicial review cases where there is genuine dispute of the laws. Even now, the Saiko Saibansho is conducting a judicial review of the Collective Self Defense initiative that had been agreed upon by the LDP and by the current administration in power. If the Supreme Court finds in its review that the initiative is unconstitutional, then it will demand the Executive (Current Administration) and the Legislature (The entire Diet and Junior Assembly) to repeal the initiative.
The Courts are considered the manifestation of the jurisprudence of His Imperial Majesty the Emperor. And thus any decisions by the Courts, especially by the highest court in the land, The Supreme Court, must and will be implemented by both the Executive and Legislative Branches.
If you mean to say that Vietnam can avail of a parliamentary style of government, then yes. Given the social constructs that differentiate Japan from Vietnam, there won't be a complete utilization of the entire system. For one, Japan is a Constitutional Monarchy, wherein the Symbol and Power of Government stems from the Emperor: The powers of the Executive, Legislative Bodies and the Judicial Body are given by the Imperial House to rule in behalf of the Emperor Himself.
Due to this dichotomy, Vietnam most certainly cannot be a Constitutional Monarchy given the lack of a monarch in Vietnam. Tho it can avail from Japan's judicial system, our judicial review system, the construction and the organization of our legislative bodies, which is based on a Bicameral system. They can avail in utilizing our independent auditing segments of government that ensures there are no abuses of power by either of the three branches.
Vietnam could avail also of other forms of democracy; a federalist form, republican form or the parliamentary form.