I solo everything. In "The Moo Manchurian Candidate" quest, it asks you to enter the banquet hall in Hamamitsu Garden, I did that and started the ninja pig fight that's inside. Before I did anything for the first turn, I noticed that the pigs were all level 50, the same level as me. I didn't like my odds so I fled right away and went back to doing other quests in Subata. I saw the quest as "defeat ninja pigs" in my questbook for a while, before it changed to a 'talk to' quest. I was curious so I went back to the dungeon and it didn't make me fight the ninja pigs, it just let me talk to the guy I was supposed to talk to after fighting them. It let me finish out the quest without doing the fight.
It's not really important, I just figured that that's not what's supposed to happen.