Ken Kaneki, your typical shy, book-loving college student, has his life completely changed after his first date with fellow book lover Rize. What Kaneki doesn't realise hower is that along with books, she also has a love of food.... more specifically, humans, for Rize is a ghoul; a monster that can only survive on eating human flesh. After being attacked by her, a somewhat coincidental accident at a construction site kills Rize, and in order to save Kaneki's life they transplant Rize's organs into him. The after-effects transform Kaneki into a human/ghoul hybrid, thus changing Kaneki's life completely as he comes to terms with his new body, living situation and hunger for human flesh. With the help of other ghouls in the area, Kaneki is able to adjust to his new lifestyle gradually as he sees that ghouls and humans are more similar than he first anticipated.
Like most supernatural anime, Tokyo Ghoul sets itself up by throwing a character into a world of monsters they are unfamiliar with in order explain things to the audience. Having already established the existance of ghouls in the world through the various reports on the news of incidents where they attack and eat humans, the way Tokyo Ghoul handles this aspect of divulging information about the world to the audience is by showing the efforts of ghouls to blend into human society and the struggle they face controlling their urges. It is quickly established that the ghouls in the series are not able to eat normal food - doing so makes them ill, and to a ghoul anything other than human flesh and coffee tastes terrible. Alongside this, the series establishes the methods in which ghouls must find nourishment - as expected, scenes of cannablism are on full display as ghouls need to eat humans to survive. While there are scenes of people being attacked, thus showing the darkest aspect of the ghouls, there are also other methods by which they attain food which evokes sympathy from the viewer. Of course the biggest proponent of this sympathy is Kaneki himself - throughout the show he is constantly at odds with trying to retain his humanity and not completely become a ghoul. His outright refusal to hurt or kill anyone else and his reluctance to eat humans opens the way to various discussions about survival and the differences in society not only between humans and ghouls, but the subsets that exist within the ghoul society too.
While ghouls are shown to be the main predators of the series they also have their own dangers to deal with. Within the series the ghoul's territories are split into regions, which leads the way to fighting between various factions. This leads into conflict between ghouls, mainly over territory and power. However, the Ghouls also have humans from the government to deal with - officials armed with weapons, who work as a police force that monitor ghoul activity, investigate any instances of crime and hunt down ghouls. This gives more weight to the issue of ghouls blending into society, as they have to live in fear of this police force who sees them as monsters instead of people. There are various discussions and thoughts on how ghouls and people can get along, mainly brought forward by Kaneki as he tries to understand both humans and ghouls due to his unique situation which places him between both.
As expected of a series with several forces in play, there are quite a few action scenes. The ghouls themelves have access to special abilities that can help them in battle, whilst the human characters have specially-designed weapons that have been created with the purpose of hunting ghouls in mind. As you'd expect from the series, the action and violence on show here is rather bloody and gory - it's not uncommon to see characters impaled and limbs lost. For those who have watched the Netflix version and are annoyed by the censorship, this version is completely uncut, although that being said, the jump between this uncut edition and the censorsed Netflix version are rather minor. While things are bloody and violent, the action and violence in these scenes aren't as gruesome as you might expect or what the censor bars would have you believe. There are some gory scenes and blood, yes, but nothing too stomach churning on how, with the violence in the series going for more of an action style than horror to scare or shock the viewer (although there is an extended torture scene near the end of the series which takes up most of two episode's runtime). These scenes do also lean on some psychological horror in the form of questioning character motives and a discussion on kindness that has some unexpected answers, tying into the central theme of the series - the question of survival and whether one should look out for themselves compared to looking out for others. The interpersonal relationships of the characters play into this concept, where each character represents some aspect of it by having someone they're looking out for, whether it's family or themselves, as characters fight for survival, love or greed.
Tokyo Ghoul can be summed up as a look at society through the eyes of outcasts; a show that cleverly ties in the concept of trying to fit in but still retaining some individualism, depicted via how hard it is to be yourself and not give in to certain urges. With the character of Kaneki trying his hardest to both retain his humanity yet fit in and find acceptance in the ghoul community, it really shows why the series has found such popularity with teenage audiences. Tying this together with some dark, violent moment, stylishly animated action scenes and a host of interesting characters and concepts, and Tokyo Ghoul proves to be a cool and rather interesting package.