In April 2012, a parent was cleaning their son's room when they found a To Love Ru: Darkness volume under his bed. After looking through the book, the parent found that besides the cover that shows lower body nudity,the volume contained a fair amount of upper body nudity. They proceeded to contact Tokyo Metropolitan Government's Youth Healthy Development Council to file a complaint arguing that the book violated the council's 2010 revision of the Ordinance Regarding the Healthy Development of Youths; the revision is known as Bill 156. The bill ensures that anime and manga containing sexual situations or poses that are considered by the government as too risque are not sold to minors under 18.
On April 9th, the Tokyo Metropolitan Council reviewed the contents of the To Love Ru: Darkness volume and concluded that the manga did not violate the law, though the council did acknowledge the frontal nudity shown on the cover. Since that date, To Love Ru: Darkness has not encountered anymore investigations from the Tokyo government.