Zenra Toukou Shuukan: Chijoku no Sanshuukan

A idol suddenly quits her job to finish high school and follow her dream of becoming a doctor. However, the most prestigious that she attends has a strange rule: each year there's a week where all students must attend naked. As an idol, Saki Haruka had been exempted from this practice to protect her reputation. However, with her job ending now, Haruka has to repay all her "debts" - three weeks of attending school completely naked! She will have to attend class, run a marathon or catch the train - all naked! As the headmaster and her friends dislike her due to the previous special status, Haruka would live through the hardest time in her life, filled with humiliation