RTA Guide/0/1 Star
The goal of 0 Star is to complete the game as fast as possible. No restrictions. DDD Skip and all forms of BLJ are allowed. 1 Star is the same as 0 star except without DDD Skip.
Rules
There are no restrictions. All forms of BLJ are allowed. Timing starts from power on and ends when the big star is collected at the end of the game.
Method
First do the Lakitu skip, and after this come to basement stair and jump on corner on the stairs. Next, do LBLJ and turn the camera for first Star Door skip and do this: Bowser in the Dark World (No Reds) Now lead to basement and do SBLJ SBLJ tutorial (1 Star)
Also see the video below for a tutorial in Japanese. https://www.nicovideo.jp/watch/sm30902792
If you don't get DDD skip, then get the sub star.
DDD Skip Tutorial (0 Star)
DDD Skip Strats based on your door position
Also see the video below for a tutorial in Japanese. https://www.nicovideo.jp/watch/sm32145162