do a kamehameha
beat him in the game
first you have to win some fights don't with the dbz special players then go to fight with future trunks.to beat future trunks do kamehame aaa!with keys that keys you know that na if you don't no that and then beat him with your favourite player.have fun.
Wait for one day then play again on the next day and he will be there
Beat Vegeta's DU to unlock him
play as sword trunks
you have to beat him then i saved the game refreshed the game pressed continue and i got him but i dont know for sure if it will work for you i beat him like 6 times with different characters
Defeat the mission "Hey! Been a While..., Goku's Return, and The Mysterious Boy"
by fighting every battle until all the drama piece's play out.
you cant because bulma briefs cant fight, only build things. though you get her husband, vegeta by beating him up with goku in story mode and to get her son, future trunks you have to pass the cell part or get kid trunks in a random scene in the majin buu saga when vegeta hugs kid trunks. unlock bulma
You have to be a dumb dumb
you can unlock it at hereos heart day shop for 200 dragon coins :P
You unlock it at level 14.