It took me a few days, but I was hanging out with Bruce Jr., J-Diddy and Tic Tac all together. The friend points required for them are all around 120k, so I just did some grinding through D-ranks until I got them all to that level, then used ~20k ryo in the party house to hang out with some random character that had under 10k points (was Annie at the time, now looks like Z-Dog might be a better idea) It was totally unintentional (until the end) because I was just trying to get the sham rock mission, and realized that I would be hanging out with all three at once… and figured it would be a cinch to get one more through party bonuses.
If someone in your village has the HoClaus, GET THE NINJA-MAS SPIRIT. With that, J-Diddy, Tic Tac (and Love Love if you have it) every single mission you run will get you 800 friends points. Doing it this way took me (I think) about 4 days.