Synchro: Hairikomu Zaiakukan

Ever since they were little, twins Itsuka and Rika could see what others could not. At first, they believed that they were seeing ghosts and spirits, but when they turned 14 they realized everything. They realized that what they saw was the depiction of regret and self-disgust in people who know that they did something wrong. They see these disturbing images whether they wanted to or not, so in many cases their curiosity leads them into trouble. In every case, these two try to bring peace to the person who holds the dark secrets.

(Source: MangaHelpers)