「緣分造就彼此成長的友誼，珍惜並體會其中的可貴之處。」
好奇心旺盛又貪玩的小男孩，在家中玩摺紙時因為紙不夠而隨手拿了桌上中元節祭拜用的金紙來摺成小船，而無意間觸犯了禁忌。男孩將紙船放入河中，隨著紙船漂流，男孩遇見了一艘神秘的鬼魂大船，男孩好奇地隨著鬼魂們進入，並與鬼差少年相遇。在船上，男孩因為活生生的存在被鬼差少年發現，後來被藏入木桶中，隨船前往冥府。不料男孩因闖下大禍而被黑白無常發現，少年也被牽連，所以兩個人一同踏上逃亡之旅。
在逃亡過程中，兩人情感漸深，但男孩逐漸感受到自己在冥府中身體漸漸消失，鬼差少年對此異常焦慮，少年很訝異自己會為男孩的遭遇感到擔心而流淚。而男孩為了安慰少年摺出一架紙飛機逗少年開心，並給予少年一點安慰。
在後續與追兵對抗的過程中，男孩和鬼差少年一同躲過重重困難，並試圖尋找出路。最終男孩在少年與黑白無常的打鬥過程中掉入海中，與少年分離，少年被黑白無常抓住，兩個人都不知對方是生是死。
故事的最後，男孩回到現世，得到了救援。當他回頭看向大海時，發現鬼差少年曾經遺留下的小冊子跟自己摺的紙飛機掉在一旁，這彷彿象徵著他們在冥府的經歷未曾完全消逝。
"Fate creates friendships that foster mutual growth. Cherish and appreciate the preciousness of this bond."
A curious and playful little boy, while playing with origami at home, ran out of paper. In his search for more, he casually grabbed some joss paper from the table, which was used for the Ghost Festival ritual, and folded it into a small boat, unknowingly breaking a taboo. He sent the paper boat into the river, and as it drifted away, the boy encountered a mysterious ghost ship. Intrigued, he boarded the ship and met a ghostly escort.
Onboard, the boy was discovered by the ghostly escort due to his living presence. To protect him, the escort hid the boy in a wooden barrel and took him along to the underworld. However, the boy’s misdeed was soon discovered by Heibai Wuchang, and the escort was implicated as well. Together, they were forced to escape.
During their escape, the bond between the boy and the escort deepened. But the boy began to feel his body gradually fading in the underworld, which made the ghostly escort anxious. The escort was surprised at his own concern for the boy's situation, and even shed tears. To comfort the escort, the boy folded a paper airplane to cheer him up and provide some solace.
As they fought off their pursuers, the boy and the escort faced numerous challenges and tried to find a way out. Ultimately, during a battle between the escort and Heibai Wuchang, the boy fell into the sea, and they were separated. The escort was captured by Heibai Wuchang, and neither knew if the other was alive or dead.
In the end, the boy returned to the living world and was rescued. When he looked back at the sea, he discovered the small booklet left by the ghostly escort and his paper airplane lying nearby, symbolizing that their experience in the underworld had not completely faded away.
