Mu Bin 
Duoduo Has A Free Door 

Duoduo accidentally found a free door that could take him anywhere, but soon the secret was known by his half sister, Xi Ya, who often bullied him. Xi Ya was somehow involved in the jewelry theft. The real thief had been tracking Xi Ya in order to recapture the Heart of Snow diamond necklace. Duoduo used the freedom gate to help Xi Ya, but he fall into the strange ruins city with Xi Ya, police officer Xu and the thief "black bear"……The kinship between the sister and brother grow quietly in the relationship between life and death……A mysterious bronze Unicorn took them into the parallel space, and Xi Ya finally opened her heart. The story traverses between reality and fantasy, bringing a strong reading experience.