Your Grandparents Are Ninjas

The "Princess of J-Pop" Akiko Yosano of Japan is getting married at your grandparents' fancy inn in the country. The inn is swarming with security guards in dark suits and earpieces, and the Japanese press is going nuts. Akiko is promised the largest diamond as a wedding present, and the famous Jewel Ninja is on the loose. Luckily, your grandparents met at ninja school, and protecting their guests is a top priority. Will you be brave enough to scale a waterfall, fight off a band of nunchuck-wielding ninjas, and save the wedding cake?