Some kisses. Nothing explicit happens.

Characters use the word "yaoi" pretty often. There can be seen yaoi manga covers, also referring to yaoi using "boy's love".

In one scene a girl frets about what color bra she is wearing, after getting the wrong impression that something was going to happen between her and a male.

There is often talk about Women's breast size

Hanako is in the bathtub. There is a pan on her legs that are sticking out (reaching up to a little above her knees), and then a closeup of her breasts that are sticking out slightly. This only lasts for a few seconds and played mainly for comedic effect as this is a running theme, but it can be quite uncomfortable.

Basiaclly nothing

The male protagonist can sometimes be seen smoking

The characters drink frequently. Sometimes a character gets drunk and tipsy, but nothing explicit happens.