Jitsu wa Watashi wa which translates to "the truth is I'm a ...". It follows a high school student who is horrible at keeping secrets who finds out that his crush is an airheaded vampire and quickly finds himself protecting the secrets of several other classmates. The plot follows the chaos that ensues as each of the characters tries to enjoy a normal high school life despite their secrets and dysfunctional personalities.
The male lead is Asahi Kuromine who is jokingly referred to as a bag full of holes since he can't lie at all. One day he decides to confess to his crush Youko Shiragami, but when he walks into the classroom he finds out that she's a vampire from Kansai and denser than a sack of potatoes. When she reveals that now that her secret is out that she has to leave he offers to cover up his knowledge and help her enjoy a more normal high school life. From there Kuromine begins to discover the secrets of his other seemingly normal classmates each of whom is just as terrible at keeping them as Shiragami. Kuromine has his hands full covering for them and getting dragged into their enthusiastic supernatural adventures.
Overall the series is kind of a shounen romantic comedy, but avoids the fanservice that is typical of this genre. The comedy is mainly driven by the crazy members of the cast who seem to have a rather slim grasp of reality who turn everyday situations into crises. There is a bit of romance to the story which the characters tend to misinterpret, leading to meddling and it flows well with the rest of the story but the story isn't completely driven by it.
I would recommend this manga to anyone who enjoys watching people overreact to everyday problems and doesn't mind a bit of literal humor from time to time. It is reminiscent of many shounen rom com series like To Love Ru but doesn't have fanservice as a major feature which gives it a bit more credibility.