Find all five shards by completing the following tasks, then talk to Trunks.

Defeat Quest 3 in the Demigra Saga.
Speak with Recon at Time Square.
Complete Parallel Quest 49.
Defeat Goku in Parallel Quest 14 or defeat Ginyu in Goku's body during Parallel Quest 18.
Complete Parallel Quest 2 or defeat Super Saiyan Goku in Parallel Quest 21.