One day, Akakura Gakuen's most popular teacher, Aoi-sensei, approached Wataru and informed him that he needed help and that he should take off his clothes immediately. He was an agent of the secret international defense organization Cradle and asked him to assist him in the battle against the enemy "4D." To defeat "4D," he must participate in ecchi activities to gain energy and defeat the enemy with the power of love! His childhood friend Honoka, his classmate Ermalit, the expressionless Tsukuba Mirai, and the petite Chitose lend their assistance. However, they are unsure of what to do. And so marked the end of his peaceful single life.