The blue doll’s name is Stitch.
Stitch is the "Experimental Subject 626" from the alien world (there were 625 experimental subjects before). Because he was created for evil purposes, the newly created No. 626 is very destructive. Strong, eventually decided to be exiled by the Grand Councilwoman.
Unexpectedly, he destroyed the spacecraft where he was imprisoned and finally escaped to the earth. In order to survive, he disguised himself as a stray dog ??and was adopted by a little Hawaiian girl named Lilo, who also received the name "Stitch".
As a result, in the days of getting along with Lilo, he gradually understood what 'Ohana (family) is, his wildness gradually subsided, showing his sincere and loyal side, and became Lilo An important partner in the family. Very popular among children.