Lot of romantic tension between Yusuke and his love interest Keiko, which leads to a few kissing scenes. Some mild innuendo, but VERY rarely.

Episode 23 starts with a fight full of innuendos and gender confusion jokes.

During a narration in episode 54, Kuwabara touches his genitals while sleeping.

A few sexual jokes that include:

In episode 1, Yusuke lifts Keiko's skirt and comments on her panties color.

A Male Character is in a stasis tank in some occasions but Zero nudity seen because only upper body as usual opposite of female characters that are showed fully nude with no graphic details but bare backsides clearly seen.

At the end of episode 42 when Keiko and Yusuke argue, the first's behind is zoomed on, then poked and commented on by Yusuke who gets slapped in return. The poking bit is shown in the opening narration of the following episode.

In episode 103, A woman's breasts can be seen briefly. But its not very detailed though.

The show starts off pretty tame at first but gets more mature as it goes on, with the Chapter Black Saga being the darkest of them all. There's a fair bit violence with blood, as well as a disturbing flashback focusing on mankind's horrible deeds like torture and murder

Kurama decapitated a teenager controlled by young toguro. Its pretty bloody.

During a fight,hiei cut off his own arm in order to kill an enemy. The scene is brutal

Toguro massacred the tournament committee. It's really graphic and violent. He killed one by flicking his finger making his head explode.

Toguro pirece kuwabara hearts and blood starts pouring out.

Sensui witness yokai being tortured by human beings. He then proceeds on killing every humans in the torture room. Pretty bloody

Karasu tortures kurama by surrounding him with bombs. Kurama is left in a bloody state

Hei cuts off a person's arm. Blood is seen coming out. And then proceeds stabbing his opponent through the head.

Doctor kamiya got his arm blasted off by yusuke.

There is a lot of supernatural animated violence, which can get pretty graphic. The main characters confront enemies by punching, stabbing, supernatural attacks (which can lead to disintegration), decapitations, amputation, and explosions. There is also a fair amount of animated gore during fights.

A lot of intense battling, with occasional blood spillages. No gore or extreme brutality.

Some of the violence is bloody, with episode 63 being the bloodiest of the entire series.

Lots of martial arts/action.

Corase languages in this series are mild and moderate.

Frequently uses of mild language. Occasional use of stronger language, but no stronger than a mild PG-13 film.

This is all in the FUNimation English dub:

Yusuke has quite a mouth on him and swears frequently. The words "Damn", "Piss", "Ass", "Hell", "Bitch", "Bastard", "Crap", "Prick" and "Shit" are used, though the word "Shit" is said in only two episodes.

The middle finger is used 4 times:

In episode 16, it is used by Yusuke.

In episode 32, it is used by Yusuke.

In episode 44, a fan in the Dark Tournament uses it.

In the Animax Asia English dub, there is no profanity.

In the Japanese version, "Goddamn" is used.

Atsuko (Yusuke's mother) is shown drinking and smoking in a few episodes. Shizuru and Sakyo are also smokers.

Early Yu Yu Hakusho is pretty tame, but the later episodes can get pretty dark and violent and are more akin to a TV-14 anime.

The dark tournament and chapter black saga are the two darkest sagas in the series.

Toguro backstory is pretty tragic. A giant demon broke into toguros dojo and massacre his pupils. In one scene a little boy is stab by the demon, you can see the boy struggling for his life. Blood is present

Sensui witnessed humans torturing and killing demons for fun. Very disturbing and intense. The comic is actually more graphic but the anime was still disturbing and chilling.

Yusuke fight with doctor kamiya was very intense and creepy

In edited versions has milder edited formats and edgier, original formats. But in unedited versions include more intense violence, more sexual humor, and stronger language.