Is it japanese or koreon?
Highlight Continue, hold Left, press R, R, L, R, L, R, L, L (after getting first 5 stars)
7 Stars
There are 7 stars you can get, which will appear next to the main title screen once you satisfy the objectives.
Unlockable How to Unlock
Blue Star (4th Star) Complete your Standard Chip Library (200 Chips)
Green Star (2nd Star) Defeat Bass GS in Secret Area 3, after defeating Dark Man, Japan Man and Serenade
Light Blue Star (3rd Star) Beat all of Serenade's "Time Trial" times in Secret Area 1, 2 and 3.
Orange Star (7th Star) Complete your P. A. [Program Advance] Library (32 Combos)
Purple Star (5th Star) Complete your Mega Chip Library (85 Chips)
Red Star (6th Star) Defeat ALL 15 Omega Navis. (Must use code to unlock Omega Navis)
Yellow Star (1st Star) Defeat the Original Alpha.