Image: Sucker Punch Productions / PlayStationOfficial screenshot from Sucker Punch Productions / PlayStation.
Cooper Clan Cosplayer is a silver trophy for dressing Jin as a famous thief. You need three items equipped together, and it opens up once you reach Kamiagata in Act 3.
Grab the Crooked Kama headband from the top of the Jogaku Temple pagoda. Finish The Unbreakable Gosaku for the armor and buy the blue dye. Take the Sly Tanuki kit from the Pillar of Honor on the Kamiagata coast east of Iwai Village. Equip all three.
Gosaku's Armor does not need any upgrades for this trophy.