Here is the full list of all 21 Naomi's Exhibition achievements.
Defeat Naomi 1 Time
Defeat Naomi 2 Times
Defeat Naomi 3 Times
Defeat Naomi 4 Times
Defeat Naomi 5 Times
Defeat Naomi 6 Times
Defeat Naomi 7 Times
Defeat Naomi 8 Times
Defeat Naomi 9 Times
Defeat Naomi 10 Times
Defeat Naomi 11 Times
Defeat Naomi 12 Times
Defeat Naomi 13 Times
Defeat Naomi 14 Times
Defeat Naomi 15 Times
Defeat Naomi 16 Times
Defeat Naomi 17 Times
Defeat Naomi 18 Times
Defeat Naomi 19 Times
Defeat Naomi 20 Times
Beat the Game