The protagonist, Nabeshima Tatsuya, was a world-renowned painter. However, after a certain incident, he disappeared from the public eye. Now as a social studies teacher, he spends his days away from the art world. He lives in seclusion with his cat in his social studies preparation room, which is his own residence, away from the public eye. However, with the arrival of the new school semester, a new wind begins to blow. Kusunoki Iroha, an attractive girl who adores Tatsuya. Kurusu Sakuya, the most talented girl in the school, who mysteriously invites Tatsuya to the school; and Akebi Saki, the daughter of Tatsuya's former teacher. A life of dullness, like being dead inside while living. Now it is being colored in gorgeous and vibrant colors by the three girls.