The harem bar has been somewhat raised as of late. While the harems of years past could get away with occasional hot spring shenanigans and the promise of a kiss, modern sex capers like Prison School and Monster Musume throw lust and nudity front and center, accompanying that with exotic rarities like largely non-human bodies and other unique flavors. It's not enough just to have a hapless male lead and a bunch of cute girls; to stand out in the modern harem landscape, you need to give the people what they want, when they want it, in forms they're not even entirely sure they want it in.

In the context of stories like that, My Monster Secret feels almost like a throwback to a gentler age. Its characters harbor simple crushes, and their feelings are constrained largely by shyness and personal density. It's still wacky and ridiculous, and yes, two of the major harem members are a vampire and an alien, but it still feels generally light and nostalgic. It's not sexy so much as charming, and not propulsive so much as breezy. It's not a great read, but it is an easy one.

My Monster Secret stars Kuromine Asahi, whose defining feature is his inability to keep a secret. So of course, within the very first chapter he learns his crush Shiragami is actually a vampire, and that if anyone else learns about this, she'll have to leave school. Promising to help keep her secret, Asahi asks if he can be her friend... and then spends the rest of the volume keeping both hands over his mouth as he tries to avoid giving up the ghost, and also maybe tell Shiragami how he really feels.

The manga starts off a bit slow, and its first half is downright weak. After the initial setup, which demonstrates an endearing chemistry between the two main leads, Asahi spends several chapters being hunted by his classmate Mikan, who basically prides herself on making secrets public. These chapters aren't really that thrilling - Mikan isn't an interesting character, the plots are entirely self-contained capers, and the jokes are mostly just anticlimaxes, since you already know the story isn't actually going to make anyone's secret public this early on. This section feels like a very simplistically written romantic comedy trying to find its feet, and going through a few one-chapter motions as it seeks an individual personality.

Fortunately, the volume's second half definitely finds one. The introduction of Asahi's class representative Nagisa, a former crush of his who also happens to be a tiny alien version of herself piloting a human-sized robot, adds a nice counterpoint to the story's two leads, and her back-and-forth with Asahi and Shiragami give the story a stronger individual texture. It's nice to see a romantic comedy where basically all of the central characters already like each other - there's no bluster or denial in Asahi and Shiragami's relationship, and they often get into small arguments like actual friends would. The conflict standing in the way of their relationship isn't some big arbitrary issue, it's that Asahi is too nervous to say anything and Shiragami's too oblivious to notice anything. It's a comedy of errors between a likable bunch of idiots, given life by its fun cast even if it's not wowing you with its storytelling.

My Monster Secret's art is generally a notch in its favor. The first chapters feature some fairly rough expression work, but the designs smooth out over time, and they possess a very unique style right from the start. Lanky and broad-shouldered, the characters look inherently older than most manga high schoolers, with very distinctive mouths and eyes. The backgrounds are competent but flavorless, as you might expect from a romantic comedy - it's the character expressions that are important, and those are consistently strong. The art isn't beautiful, and often doesn't seem traditionally “cute” either (the characters' lengthened faces and angular bone structure stand in contrast to modern assumptions of manga adorableness), but it's consistent and full of personality.

Overall, My Monster Secret is an enjoyable, unassuming version of exactly what you'd expect it to be. Its characters are simple but endearing, possessing enough personality and chemistry to bring life to its classic genre motions. There are cute moments and funny moments, plenty of gags that work and also a fair number that don't. It probably won't wow you, but if you're looking for an earnest, old-school romantic comedy/harem, you could certainly do worse.