Easily unlock: Chinpokolypse, More Popular Than John Lennon, Clothes Whore, & Full Arsenal

The save starts at Jimbo's. You want to teleport to the chest above them to get the final two weapons. Then, head to the sewers using the entrance by the movie theater. Break the barrier with Nagasaki and follow the path. You will find the final Chinpokomon which gets you the next-to-last friend. Talk to the crab to get the last friend. Loot the chest to get the final outfit.