You can get this by either completing the first 3 quests fully and by just finishing the fourth or if it seems too hard you can do the first 5 to 2x stars.
Requirements (blue, yellow, red stars in order):
001: Ninja Research- Clear the quest (beat Ayane with Kasumi)
- Inflict 35 damage with a single combo (smashing the enemy into a wall with kicks definitely gets you this)
- Perform 1 ground attack (when the enemy is laying on the floor, either press
from close or
+
from afar)
002: Chinese Martial Arts Research- Clear the quest (beat Jann lee with Leifang)
- Inflict 35 damage with a single combo (same as 001)
- Land 3 hits on a sidestepping opponent (Side step is done by pressing
or
and
once, the character does a specific sound and kind of goes crouching. You have to hit the enemy when he does this. This may be easy or annoying depending on the cpu, but you can force sidesteps by hitting the enemy once then holdin
and walking around him constantly. Eventually he starts side stepping, usually a few times in a row. A simple punch
should be enough to hit him quickly - don't forget to let go of the other buttons. Remember you have to win 2 out of 3 matches so if you can't do it in two rounds then let him win one and you can try more.)
003: Military Combat Research- Clear the quest (beat Christie with Bayman)
- Fill the Break Gauge by 30 with a single combo (any longer combo nets you this but if you want be sure then punch the enemy a little and before she falls down do the Fatal Rush
and you definitely get this)
- Clear the quest within 1 minute (just push the enemy to the wall and go to town, some punches then kicks and then kicks again when she bounces back)
004: Pan-Pacific Research- Clear the quest (beat Jann Lee with Hitomi)
- Inflict 35 damage with a single combo (same as 001)
- Hold 2 mid punches (This is done by pressing away from the enemy and hold at the same time just when a mid punch comes at you. By default this is
standing on the left side of the screen. Mid punches are generally aiming at your midsection. If you are new in the game then it is pretty much mashing the hold and hoping for the best. Don't forget you can lose one round to have more time to get it.)
005: Revenge of the Lost Arts- Clear the quest (beat Brad Wong with Eliot)
- Inflict 35 damage with a single combo (same as 001)
- Hold 2 high strikes (refer to 004 mid holds, the difference is now you have to press
to counter)
Alternatively if you are really struggling with this then simply beating the first 10 challenge gives you 10 stars because the Blue Star is always simply winning the fight.