Mysterious Girlfriend X - Recommendations

Alt title: Nazo no Kanojo X

If you're looking for manga similar to Mysterious Girlfriend X, you might like these titles.

Spy x Family: Family Portrait (Light Novel)

Spy x Family: Family Portrait (Light Novel)

In this book of Spy x Family original prose stories, Anya attempts to make friends with her target Damian during an Eden Academy camping trip, Yuri spends his day off babysitting his niece, and Franky seeks Loid’s help in winning the heart of a blind opera singer. Then, when the family sits for a portrait painting, Yor is terrified that her secret identity will be blown. And in the final story, the family is scrutinized by a pair of unseen observers... There’s never been a family quite like this one!

I agree

Shinigami Tsuki no Amamiya-san: Shinigami Yousei Gakkou-hen (Light Novel)

Shinigami Tsuki no Amamiya-san: Shinigami Yousei Gakkou-hen (Light Novel)

Chifuyu Amamiya, a high school girl who is lonely for a lifetime. I am haunted by a handsome (self-proclaimed) Shinigami, and I'm in trouble because he's stalking. In addition, a group of “God-like Poems” such as “Victory Goddess Possession” and “Inari-sama Possession” and teachers of “Rice God Possession” will appear more and more. 

I agree

Fukanzen de Fueisei de Fushidara

Fukanzen de Fueisei de Fushidara

Yugami Maiko is a girl with a fetish for teeth. Hizumi Ryuuji is a guy who hates his crooked and unslightly teeth.

I agree

Saiki Kusuo no Ψ-nan: Extra Story of Psychics (Light Novel)

Saiki Kusuo no Ψ-nan: Extra Story of Psychics (Light Novel)

New disasters for ESPer Saiki Kusuo… Nendou starts talking about Nietzsche, Kaidou becomes a Wizard at Kitsune High…!? Caught in the trap of a jumbo ramen challenge, and what’s the reason Saiki is absent from school…!? A novelized compilation of daily life stories. Celebrating the 1 year anniversary of serialization for the popular JUMP manga Saiki Kusuo no PSI nan! What new disasters await Saiki? A collection of 5 short stories, 4 extra short stories, illustrations, and pull out posters.

I agree

Otoko Girai na Class no Bijo ga, Jitsuha Brocon da to Shitteshimatta Kekka. (Light Novel)

Otoko Girai na Class no Bijo ga, Jitsuha Brocon da to Shitteshimatta Kekka. (Light Novel)

I agree

Ureshon!

Ureshon!

I agree

Henkoi!

Henkoi!

The main character finds his possessions "abused" by some unknown person until he finally caught the culprit... masturbating to them?

I agree

Jujutsu Kaisen: Summer of Ashes, Autumn of Dust (Light Novel)

Jujutsu Kaisen: Summer of Ashes, Autumn of Dust (Light Novel)

Cursed spirits have struck the opening blow at Satozakura High School in an unfolding conflict against the Jujutsu Sorcerers. But while this epic and unyielding battle intensifies, the heroes of Jujutsu Kaisen have other mysteries to solve…such as why Yuji and Megumi see Gojo at a maid cafe, whether Nanami can uncover the secret behind a website that claims to sell dolls that resurrect the dead, and what happens when a blind old man is able to see the scheming Mahito.

I agree

Tsuyuno-chan Likes to Show Off

Tsuyuno-chan Likes to Show Off

Nozomi-kun is a middle school boy with an armpit fetish. One morning on the train, he spots Tsuyuno-chan, a high school girl who's a bit of an exhibitionist. Immediately entranced, he follows her to her basketball practice. But when she spots him, she decides it might not be so bad to just indulge him?!

I agree

S Watari-san to M Mura-kun

S Watari-san to M Mura-kun

Intelligent and beautiful female high schooler Reika Sawatari and handsome and astute male high schooler Subaru Emura, both of whom with a certain fetish that nobody knows, have started their relationship after a certain event.

I agree