Some mild fanservice. Cleavage, panties and so forth.

Female characters have romantic feelings/lust for their brother.

Girls make multiple attempts to seduce a boy. One girl intentionaly walks out of the bathroom in only a towel.

Slapstick type stuff. The girls have a memory hammer that erases the short term memory of the peson struck in the head by it. Which is usually the male MC ...and often.

The girls call each other "bitch" and "slut" on the regular.