If there are exactly two permanents named Brothers Yamazaki in play, the "legend rule" doesn't apply to them.
Each other creature named Brothers Yamazaki gets +2/+2 and has haste.
The two Brothers could be controlled by different players.
There are two versions of this card, each with different art. The cards are numbered 160a/306 and 160b/306. The art has no effect on game play.
If a third Brothers Yamazaki enters the battlefield, the legend rule will apply. If one player controls more than one Brothers Yamazaki at that time, that player will have choose one and put the rest into his or her graveyard.