It's not too often we get a full-on yuri harem manga, and this first volume is eager to show off both of those aspects immediately. By about page three, before we even hit the table of contents, our love-lorn heroine has declared no less than five times that she is going to get a girlfriend. By the first chapter's end, she's had run-ins with five beautiful women who are all very interested in eating out with her (if you catch my drift) and woken up naked in bed with one of them. Where other harem series might slow-roll the introduction of their love interests, I Don't Know Which Is Love is all about wallowing in the delirious indecision of being the cheese in a quintuple-decker girlburger, and has no patience for anything approaching subtlety.

That audaciousness is both this volume's greatest strength and biggest roadblock. While the story is ostensibly about Mei being torn between her various suitors, “love” is a bit of a strong word for what she's experiencing right now. While each subsequent chapter of this volume fleshes out one of the women beyond their introduction, Mei's connection with any of them ranges from being smitten to being overwhelmed by their beauty. There is certainly room for building upon those reactions, as well as delving into more drama as each of Mei's potential lady loves finds out about the others, but that's only hinted at in the final pages of this volume. It feels like going through the opening chapters of a dating sim, introducing each girl in broad strokes, with the promise of building a deeper connection some time in the future. In the here and now, it's pure romcom silliness, as Mei finds herself thrown into the deep end of the Thirsty Lesbian wave pool and struggles to keep her head above water.

However, if you're in the mood for something light and fluffy, this volume is pretty fun, thanks largely to the varied personalities and unique gimmick given to her harem. Each woman has a different fixation based on one of the five senses, giving them each a unique facet of attraction towards Mei. Bashful classmate Riri is obsessed with touch, keeping the sense of her hand on Mei's cheek close to her heart. Maria, Mei's academic advisor, has an eidetic memory and wants to fill her head with cute images of her students. Roommate Kaoru has a preternatural sense of smell, to which she can sniff out the scents of all the other women Mei encountered throughout the day, and is keen to wash those aromas away with her own. My personal favorite is the princely Minato with her sensitive hearing, who pines for some proper lesbian ASMR material but has to suffice with hearing Little Sister characters proclaim their love for “Onii-chan” instead of “Onee-chan” for the time being. They're simple gimmicks, but do well to make the characters – and their intimate moments with our protagonist – feel distinct.

Yes, by the way, there are a lot of physical scenes here. While there are no uncensored nudity or full-on sex scenes, every chapter features at least one sequence of a lady getting very familiar with Mei, ranging from some light petting to second base. There's nothing super steamy in this first volume, thanks to several convenient interruptions, but it's overtly and unabashedly sexual nonetheless. Some of the scenarios could be off-putting for readers, with just how eager most of these ladies can get. Karin, the self-proclaimed “Kiss-crazy Senpai” literally says hello by tongue-wrestling Mei, which is at least a little inappropriate, even if Mei agreed to kiss her beforehand. Similarly, Professor Maria is probably due for a disciplinary hearing after staying the night at a hotel (no, not that kind of the hotel) with a student, even if they slept in separate beds. The biggest, most stereotypical ecchi moment is when Mei wakes up to find Kaoru has stripped her naked and cuddled up in her bed during the night – with the flimsy explanation that Mei's fabric softener was too strong for her nose. These moments are tempered by knowing Mei is 100% down to clown, and in later scenes both Kaoru and Karin get explicit consent before re-engaging, but folks sensitive to aggressive or forward sexual encounters should take note.

In all though, this volume is a light, breezy bit of harem fun delivered with just a hint of spice and the promise of more. Tamamushi Oku's art is simple, but expressive and effective at capturing the different energies of each character. The biggest question is whether or not this story will stay a lighthearted romp, or start digging into more serious drama. The most tangible hook is Mei's confusion with her feelings, struggling to figure out whether being attracted to all these women is the same as being “in love” – and how much that means to her when it comes to a sexual relationship. The closing chapter hints at some deeper secrets with Karin as well and promises some drama with the insecure and somewhat clingy Riri. In their afterword, Oku admits they don't have a clear idea of where the story is going, and are just running with the idea to see where it goes. So it's anyone's guess if this first volume will be indicative of the rest of the series or not. Regardless, this is a solid introduction that has a lot of gags – and cheesecake – for fans of harem manga, yuri manga, and especially for both.