A legendary love comedy manga that boasts tremendous popularity. Since it began being serialized in 1997, it has continued to attract many male fans and is still popular without fading.  As the author's message "This is not just H manga", by not only describing sex simply, by arranging characters with various values,  It is often composed of quotations such as male/female psychology and romance/marriage/sex/sex/sex differences between men and women, quotations, and personal opinions of authors.  It is published in 12 countries around the world, including Koreans, Taiwan, the United States, and France.