Megane no Shoujo

With her we are dealing with an ice-cold bride, with whom one would freeze to a block of ice just by looking at her if one could look into her soul. She takes the train to school every day and if a male gets lost to her - she always stays in an intermediate compartment of two cars because of the crowd on the train - the latter is invited to a game to which almost no guy can say no. It's very simple, she asks a question (e.g. who gets on first at the next station or who sits down first when a seat becomes vacant) and if her play partner guesses correctly, he gets a reward. It starts with the good old handicraft and goes all the way to coitus. Now everyone could consider themselves lucky who is invited by her to such a game, because she is a really very attractive female. But she has a final climax in store, after the "climax", which her play partner would probably not really expect. The next morning she stands on the platform smiling again as if nothing had happened and listens to the latest gossip.