One character's father is a drag queen who works in a club.
The series features sexual innuendo that will go over the heads of young viewers, as well as lots of LGBTQ+ subtext throughout. Some kissing and romantic interests. There's also lots of LGBTQ+ associated references designed to be titillating, but the relationships never fully play out.
In one scene, a character attempts to show a girl that some of her previous actions were dangerous. He is seen dimming the lights, grabbing her wrist forcefully, and pinning her to the bed, him shirtless and her in a sun dress or nightgown. She reasons with him and realizes he was simply trying to intimidate her and had no real intention of harming her.
All members of a certain female-only club have a lesbian romance.
In another scene a girl and another girl accidentally kiss (it was meant to be a peck on the cheek but one girl was knocked into the other), and an image of this is shown later in the series.
Some members of the Host Club often fawn over the protagonist (hug her, fantasize about her in various getups, etc) but this is all harmless and never graphic, simply the crushes of a few teenage boys.
The show centers around a group of boys running a host club, in which they entertain guests and host various events. This is more romantic than sexual, with the boys just having tea and talking to the girls in a romantic way, and is never graphic.
Each host has an individual character type they use to attract guests. Identical twin brothers use "brotherly love", which is described as a somewhat taboo, mischievous relationship between brothers, although this is mostly an act to entertain the guests. Nothing graphic.
A girl pins a boy to a couch suddenly when she realizes he doesn't love her. The scene cuts before anything happens.