We utilize statistics in our daily lives when we evaluate TV program ratings, predict voting outcomes, prepare stock, predict the amounts of sales, and evaluate the effectiveness of medical treatment. We predict the result not on the basis of personal experience, but on the basis of data. However, the accuracy of the prediction depends on the data, the theory, and the depth of understanding the model. In this book, the author analyzes fundamental models to advanced models without skipping their derivation processes. It is then possible to clearly understand the assumption and approximations used in the model, and hence understand the limitation of the model. We also cover almost all of the subjects in statistics since they are all related to each other. Although this book treats advanced models, people who are not professional in science can easily understand the content since by stepping up the derivation from the fundamental level to the advanced level. The author does hope that readers can understand the meaning of the models in statistics and techniques to reach the final results.