Description: The St. Joachim Academy for elite girls booked the maiden voyage of the new Marine Express submarine train, which runs along the ocean floor from the sunny California all the way to the Japanese coast. The journey seems like the perfect opportunity to enjoy the beautiful underwater views, learn a bit more about marine biology and, ultimately, relax from the usual school life. However, the idyllic travel turns into a nightmare when one of the accompanying teachers appears dead in his room. Who could have killed the most popular and beloved professor in the academy? A mystery visual novel taking place aboard the underwater train Marine Express. Follow student Ranko Togawa on her quest to find the culprit on the murder of an accompanying teacher... with lots of surprises along the way!