Looking for trippy manga? Your in luck, both Voynich Hotel and Baketeriya are series of that sort. Voynich Hotel is considerably more trippy than Baketeriya, but the latter isn't lacking in that department to begin with.
While trying to escape from Marie, a homicidal, troubled girl who's infatuated with the man, Rokusuke stumbles into an inn to hide. But little did he know that it's no ordinary inn – in fact, the establishment is run by a supernatural witch named Okami who kills those that don't pay! What's worse, Marie decides to stick around as well to become a maid, and she's determined to not let anyone else get their hands on her crush. With plenty of danger ahead, Rokusuke must survive each day, dodge Marie's advances and learn about the history of the inn and its unusual inhabitants.
Both Karakasa no Saien and The Voynich Hotel take place in a hotel\inn in which both the staff and guests are weird (in a very twisted way). If you liked one of those two, you might want to give the other one a try.
Mikaya moves into an apartment building filled with eccentric tenants, including a girl obsessed with decomposing corpses, a door-to-door butcher dressed as a Revolution-era French aristocrat, and a man who always wears swim goggles and rarely leaves his bathtub. But the strangest thing about this apartment is the man who previously lived in Mikaya's room, K. Though his body was never found, everyone is convinced that the man died - a fact that puts the girl in the middle of a peculiar and bizarre mystery...
Another manga about a guy that's recently moved into a hotel/apartment, and everyone else staying there is completely outlandish. Most are weird in a creepy/macabre way.
Voynich Hotel is fairly normal in terms of art and storytelling method, whereas K no Souretsu is just as odd as it's cast, but if you liked one you may want to look into the other.
Both of these manga have extensive casts of ridiculous characters that are always up to something. Combined with the short chapter length, both manga feel like they're in constant motion- there's not really any downtime.
Both stories are kind of dark (especially Nokemono), but hide it under cute graphics and silly humor.
Liked the Voynich's trippy plot and the really-weird-yet-somewhat-fun characters? If yes, then don't forget to give a look at Oddman 11 as well; the atmosphere in both of these series are very similar (after all, they are written by the same author...), despite having two almost completely different settings.
As for the weird characters, well, you'll certainly have your giant share of them...