Falling into the rather niche genre of 'visual novels', pretty much all of your time in Hakuoki will be spent reading and clicking through reams and reams of dialogue, so being a confident reader is a must – particularly as you come across a lot of Japanese words and terms that may trip younger children up (although all the terms are defined in the game's handy Encyclopedia). With little in the way of what would traditionally be classed as gameplay, this is one for those who prefer their games to take a slower, more thoughtful pace, with the only input you really get in the game being the occasional choice between a couple of conversational options at certain branches in the story, which open up new paths and helps draw you closer to your chosen guy. Dealing with more mature themes like love and relationships, as well as making sense of the political conflict sweeping the country, this is a game that's probably better suited to an older, more mature age group of teens and up – even if what you do isn't particularly demanding.
One of the story's threads involves a mysterious mixture that transforms all who drink it into demonic versions of themselves – with a complication known as 'bloodlust'. Driving them mad at the sight or smell of blood, the crazed characters repeatedly hack at the bodies of their victims until they're unrecognisable (although you only read about and never see the aftermath). To suppress this condition, the protagonist learns that she can feed the afflicted men her blood – leading to some slightly strange scenes of men licking at self-inflicted cuts on her arm.
Being a game which revolves around the fostering of a romantic relationship with one of a number of men, sex and love do feature, albeit not particularly heavily. Most of the relationships are fairly innocent, with nothing particularly questionable going on, although one route in particular implies the protagonist and her partner have sex. The only things you see are first a picture of Harada lying above Chizuro, followed by a close-up of their entwined hands, with fairly wishy-washy and not-too-graphic descriptions - "no matter how wrong a union between [snip!] might be", "I heard the cord of my pants loosen" and "as our bodies became one". Outside of this particular incident, it's mostly occasional kisses, accidentally falling on top of men and a few references to some of the commanders' visits to Kyoto's red light district – with the occasional joke alluding to the guys' escapades with women and their drinking habits.
A final note is that the game does have a fair amount of swearing in – from Hijikata declaraing that the Shinsengumi are "not about to p*ss ourselves over a demon or two" to the mid-battle expletives of b*stard and f*ck, Hakuoki isn't the cleanest of games.