A girl who was raised with love in a wealthy family. But the home was strict and she was suffocated by her constant cram school and extracurricular activities. There was only one place where these girls Kokoro relax. It was the shack of a dirty-looking but kind old man whom they met in the park. The girls called it their secret base. But one day, the old man was excited by the defenseless girl and bared his fangs!