After spending busy days with people and yokai, Takashi Natsume meets his old schoolmates, Daisuke Yuki, and remember the bitter time with yokai in the past. At the same time, Natsume meets his grandma’s old friend, Yorie Tsumura, who Natsume saw in the memories when he releases yokai’s name. Yorie is blissfully living with her son, Mukuo, but it seems that a mysterious yokai also lives in their town. After Natsume’s investigation, the ＂seed of yokai＂ which Nyanko-sensei got grow into a huge tree in one night and Nyanko-sensei split into three little Nyanko-sensei after eating fruit of this tree! What happened to Nyanko-sensei?