This review contains little/no spoiler content. Enjoy!!
A couple years ago in 2021 I heard about a certain manga series in a YouTube video, and upon hearing what the YouTuber had to say about it I vowed to never read this manga after realising it was just some spit fetish series without any substance. About a year later in 2022 this forbidden manga found me again, and without realising why I thought it to be so familiar, I began reading. In the present year of 2023, I look back on that sequence of events as one of the best mistakes I've ever made regarding my time consuming anime and manga.
Themes:
In case you haven't guessed already, the forbidden manga I accidentally read was Nazo No Kanojo X or Mysterious Girlfriend X, and in case you skipped the intro, the main themes of Nazo No Kanojo is, to put it bluntly, The Writer's Poorly Disguised Fetish. Spit play will probably be a deal-breaker for some people, especially since it is featured in nearly every chapter. I should know, as it was what turned me off the series initially. However the body fluid theme isn't just cheap, niche fanservice, and really helps to characterise the main leads, but I'll mention that at the end. Just know that even though this aspect can be a hard swallow (no pun intended) it's worth it, or at the very least utilised well and serves the story and characters.
The other themes aside from Romance/Comedy are just general Ecchi elements throughout. I typically don't mind Ecchi/fanservice content in a series, and I am usually happy to just ignore it whenever it arises, but considering the underlying motifs of growing up and adolescence in this manga as well as the lack of cheap tricks used to incorporate it, the Ecchi in Nazo no Kanojo gets a gold star from me.
Story:
To the surprise of no-one, this RomCom manga pulls a revolutionary move which has never been done before and features characters who are in high school, so the typical school-setting arcs, that people who consume too much slice-of-life like I do will recognise instantly, are present here, such as the cultural festival arc, a spontaneous youthful excursion to the beach by train, ect, ect. Despite this, Nazo No Kanojo injects it's own flavour into these otherwise average and overdone story beats, and doesn't just rely on Urabe's quirks to carry every part of the plot, and genuinely creative plot points are created to avoid this. However even the self-contained chapters which don't have a huge bearing on the plot and typically aren't referenced again in the series are still a delight to read by virtue of Urabe and Tsubaki just being so entertaining to read about, and this consistency in character quality allows the story to just flow naturally around them.
Characters:
Nazo No Kanojo's biggest strength, much like with most RomCom series, lies in it's characters. A lot of other series similar to this manga may fall due to a lack of compelling characters, and, ahem, other (ecchi) elements taking centre stage, yet Mysterious Girlfriend X strikes a great balance between the two.
The titular Mysterious Girlfriend Urabe Mikoto is easily one of my favourite leads in a romance series. In my mind the Kuudere archetype was perfected when Riichi Ueshiba put pen to paper and Urabe was conceived. She delivers on the Mysterious aspect of the series in droves in the early parts of the series, with her behaviour being entirely antithetical to that of a typical, happy-go-lucky deredere girl that might be more commonplace, and the iconic reacurring scissors-in-panties joke (no I'm not kidding) should be more than enough to sell anyone on her.
The male lead Tsubaki Akira more or less a typical male lead for a series of this vein. He definitely has good moments throughout the series, and I in no way dislike him, but when compared to the majesty of Urabe it's easy to view him as unremarkable. There are some points in the series where Tsubaki might blend in with the supporting cast, but overall not a bad lead compared to other male leads that reader may be familiar with from other series.
Art:
I honestly cannot praise the art enough in this series. I have a huge soft spot for a 2000s manga artstyle, but bias isn't even required when praising Nazo No Kanojo's artwork. There are several points in the manga, mostly towards the beginning and end, depicting dreams that Tsubaki has had which contain Urabe. This could be used as a cheap fan-service moment in any other work, but in this manga it is a source of pure awe at the amount of detail displayed.
Finishing Thoughts:
At it's core, Mysterious Girlfriend X is a story about growing up, and how even though settings and circumstance may change as time progresses, the bonds that you make with people closest to you are truly timeless. I refrained from putting Supernatural among the themes section in this review as I believe that there is nothing Supernatural about the spit-bond that Urabe and Tsubaki share, and that it's merely their bond and relationship that allows their feelings to be transmitted in such a way, and that this was intentionally ambiguous in order to convey this message.
It's embarrassing that I connected with a stupid 2004 Ecchi manga in such a strong way, and that I'm looking in such detail at it's story and characters when some might say it doesn't deserve such attention, but I truly believe that this series is different to others of it's calibre, at least to me. But who knows? Perhaps the real Mysterious Girlfriends were the friends we made along the way...