Brown bear Bug is a lucky guy. He was spoiled by his adopters and lived a comfortable life. However, he was released into the forest. Bug, who was not used to the hardships of nature, wanted to go back to the city. The appearance of black-tailed deer Elliot changed his plan. Elliot had one horn broken by a hunter and was tied in a car and transported to the town. Bug hesitated again and again, and finally rescued Elliot. This decision made Bug unable to return to his previous life smoothly. Elliot regarded Bug as a brother, followed Bug, and lured him to the wild jungle to "enjoy". When Bug came to the jungle, he found that the conditions here were too bad and not as comfortable as in the city. Moreover, they made a mistake and let the animals fall into the hunting area. In the face of many dangers, Bug's wildness was gradually awakened. He and the animals formed a corps to fight against the enemy and staged a vigorous battle to defend their homeland.