The 'Uso' series by Campus is a series of games, each focused on a different heroine who is in love with the same protagonist. That protagonist possesses the ability to hear lies (note that he doesn't hear truth), due to a magical artifact accidentally implanted in his body half a decade before the story begins.  The last game in the series, Fuyu Uso, will be coming out in July and covers the final heroine, the school president.   The other three heroines are Satsuki (Haru Uso) the school idol who lies as a matter of course, Izumi Aoi (Natsu Uso) the protagonist's somewhat straight-laced kouhai and ex-girlfriend, and Eris (Aki Uso) the vampire who lives with the protagonist and is his partner in the Cat's Hand Club.

The Cat's Hand Club is a club the protagonist created to give him an excuse to take requests from people, which grants him the magical energy to keep the artifact inside his body from killing him outright.  It has a terrible reputation, primarily because the 'price' the magical contracts that give him his energy extracts from his clients.  Those prices vary based on the contract and are either something unpleasant to the client or of value to the protagonist.  As an example, one client has the price of dropping his wallet at some later date.

The protagonist of the story is highly perceptive... outside of romance.  His experiences with his ability to hear people's lies have given him a solid grasp on most of the reasons why people lie, as well as helping him come to peace with the naturally deceptive nature of his fellow humans.  However, he himself refuses to lie, saying what he thinks outright most of the time, attempting to be honest both in word and in action inasmuch as possible, as well as avoiding promises that might be broken later.

Haru Uso

This game is the first one and the others that come after are based off of the story of this one having progressed to a certain point (which they don't make entirely clear).  It is focused on Himeno Satsuki, the biggest liar in the school, who also happens to be the most beloved girl in the school.  It begins with her confessing her love to the protagonist and it really gets started with her convincing him to take a request to be her boyfriend for ten days. 

If I can say one thing about this one, it is that the way the writer presents the romance in this game is... twisted.  The relationship born from Himeno's request is interesting, and Himeno herself is an interesting character.  She is highly jealous, aggressive in love, and more than a little bit of a schemer.  The writer in this game did a very good job of building her character from the ground up, as well as constructing the basic outlines of the protagonist's relationships with the other heroines. 

Natsu Uso

This one is focused on Izumi Aoi, the protagonist's kouhai, a member of the student council, and the protagonist's ex-girlfriend.  In the same spirit as Haru Uso, it begins with a startling scene where the protagonist wakes up naked in Aoi's bed with no memory of how he got there.  Obviously, this is the beginning of yet another relationship twisted by circumstance into some really odd directions.  A lot of the twisting comes from Aoi being a classic tsundere much of the time (saying the opposite of what she means), and the rest comes from the protagonist's inability to tell lies but unwillingness to tell her the whole truth of what is going on in his life.

The bare bones of the relationship with Izumi put together in Haru Uso gain flesh in this path, as the protagonist recalls the events that led to them becoming lovers and breaking up.  Aoi herself is extremely twisted up inside by that experience, and the protagonist has an intense sense of guilt coming from the events of a year before, that tends to lead him into some misguided actions.  This makes for an interesting romance, to say the least.  Similar to Haru, this game does a good job of building up the heroine, though it had less work to do in that direction due to Haru Uso.

Aki Uso

Aki Uso focuses on Eris, the heroine that is arguably closest to the protagonist, both in terms of living quarters and their relationship.  She has known him the longest of the four heroines, and she fell in love with him first, though she has done a pretty good job of suppressing it.  She is also a pure-blooded vampire, a wannabe NEET, a heavy gamer, and an extreme otaku.  If you asked me who makes the biggest impression at first glance, it would definitely be her, simply because of the degree to which she gets along with the protagonist.

Naturally, Eris's issues with the vampiric world are the largest focus of the story, with the romance occurring alongside and as a result of those issues.  I will say that Eris's family sucks and her maid is a bit weird, even compared to her. 

Of the first three heroines, her character is perhaps developed the most effectively, though this is more a matter of her placement in the story than any other issue.  It is also in her story that you start to get an idea of what Fuyu Uso's heroine is like under that constantly-smiling mask of hers, though only indirectly.  Again, I am going to praise the level of detail in the character development here, and the romance is once again twisted by various issues, both external and internal between the two.  Since this seems to be the pattern of the series, I wasn't really surprised by the time I got ot this one, though. 

Conclusion

An interesting series, so far.  I do wish that I'd waited until the final game came out, but I lost to my curiosity.  For those who like deep character development and weird romance, this is a good choice.  I won't recommend this to people who prefer the straightforward romances common to charage, though.