To obtain stars to purchase items from the Star Shop, you simply clear a battle in the Dragon Ball Collection.

Once you do, re-select the battle again but make sure to select the Hard difficulty. You'll spot a new feature called "Mission" that will detail what you need to do to earn stars for the Star Shop.

Each battle now will have objectives each worth stars. One of the three objectives will always be to simply win the fight on the Hard difficulty.

Perform the actions below to unlock additional characters:

    * Broly, Super Broly, LSSJ Broly - Complete Beat Freedom! (What-If Stories)
    * SSJ3 Broly - Complete The Legendary Super Saiyan Reborn (Secret battle 39: Legendary Super Saiyan Saga)
    * SSJ3 Vegeta - Complete The Strongest Super Saiyan 3 (Secret battle 47: What-If Stories)
    * Super Gogeta - Complete Fusion & Potara Part 1: Super Gogeta (What-If Stories)
    * Vegito, Super Vegito - Complete Fusion & Potara Part 2: Super Vegito (What-If Stories)
    * Videl - Complete The Student (What-If Stories)

These titles can be unlocked by performing the actions below online:

    * Astounding Power - Achieve rank A
    * Bomb Maniac - Earn 10 victories with the Explosive Wave
    * Capricious Warrior - Win 100 battles in cell games stage
    * Counter Monster - Execute 5 counters in a battle
    * Dirty Work - Take 5 Upwards Attacks in a battle
    * Earth-Raised Namekian - Play 10 matches in a row with Piccolo
    * Earth-Raised Saiyan - Play 10 matches in a row with Goku
    * Elite Warrior - Earn 10 victories online
    * Embarassment of the Clan - Lose 10 Saiyan-on-Saiyan fights
    * Energy Absorber - Win 10 times by absorbing energy
    * Fireworks Master - Execute 5 Upwards Attacks in a battle
    * Flying Dragon - Execute 2 Air Combo in a battle
    * ginyu force member - Use each ginyu force character 2 times
    * Golden Warrior - Record 50 victories with Super Saiyan Characters
    * Grim Reaper of Justice - Win 100 battles with Gotenks
    * Incomplete Power - Achieve rank G
    * Invincible Warrior - Earn 20 victories without a loss
    * Just a Bluff - Lose 20 times even though you transformed
    * Legend Killer - Defeat Super Saiyan Characters 100 times
    * Legendary Warrior - Earn 100 victories online
    * Lightning God - Win 50 times with Plasma Aura
    * Low Class Warrior - Default
    * Martial Arts Warrior - Execute 30 Hits in a battle
    * Nature Lover - Win in the Wasteland field without destroying anything
    * Preliminary Qualifier - Record 10 victories in the World Tournament stage
    * Prince of Cruelty - Execute 5 Knockdown Attack in battle
    * Proud prince of the Saiyans - play 10 matches in a row using Vegeta
    * proud prince of the saiyans - play 10 matches in a row using vegeta
    * Red Ribbon Army - Defeat Goku with Android characters 10 times
    * Saiyan Killer - Defeat Saiyan Characters 100 times
    * Strongest in the Other Wold - Win 50 battles with Angel Halo equipped
    * Super Elite Warrior - Earn 50 victories online
    * The World's Strongest Warrior - Earn 500 Victories
    * The World's Strongest Warrior - Earn 500 Victories online
    * Turtle Practitioner - Earn 10 victories with the Kamehameha
    * Ultimate Fighter - Win 10 times using an Ultimate Attack
    * Unknown Power - Achieve rank D
    * Warrior of Light - Use Solar Flare 10 times in a battle
    * World Class Speed - Execute 10 Vanishing in a battle
    * Wussy Warrior - Earn 10 victories by running out of time