"…I can see…the doors to people's hearts." Ai Nekomori can see the "doors" to people's hearts. He hears the thoughts of everyone around him and has learned that what people think and what they actually say are often very different. Therefore, he doesn't trust anyone and never opens his heart to others. Then he meets the upbeat, tomboy Ritsu Sengoku, who honestly says whatever she's thinking. Can she open Nekomori's heart?