What is hooray in Japanese?

There isn't a direct translation for "hooray" in Japanese that conveys the same level of enthusiasm. However, here are some ways to express similar sentiments:

Formal:

* 万歳 (banzai): This literally means "ten thousand years" and is used as a cheer, similar to "hurrah" or "hooray." It's often used at celebrations or to express strong support.

* おめでとう (omedetou): This means "congratulations" and can be used to express joy and happiness.

Informal:

* やったー (yatta): This is a casual exclamation of joy, similar to "yay!" or "woohoo!"

* すごい (sugoi): This means "amazing" or "incredible" and can be used to express excitement and approval.

* 最高 (saikou): This means "the best" and can be used to express enthusiasm and delight.

The best option will depend on the specific context and the level of formality you're going for.