(from ebookjapan):
Mangaka Shotaro Ishimori received a strange letter from his friend Yuji Amemiya, who disappeared more than 20 years ago. The letter asked him to take a look at the lining of the sliding door of the room where he used to lodge. Ishimori visited the old family mansion as instructed and found a handwritten note taped tightly to the sliding door in the four-and-a-half-tatami-mat "kiri-no-ma" room. When he opens the fusuma, which Amemiya had warned him not to open... "there" is a gateway to another dimension!　Ishinomori's definitive seinen SF series, first serialized in 1978!