Who knew Yashiro had siblings, triplets to be exact. Yashiro was left to raise her siblings after their parents died in a car accident and the now traumatized little brother who was with them on one of their business trips in Tokyo. Now with no one to look after them (except for the maids and butler) she has to take over the family business and to not be fooled by the couning business associates who will try to use her for there own gains. She has to balance out on being a student, CEO, big sister, parental figure and a assistant of no. 7 of the seven school misteries.