I was in despair because of my miserable life. This all changed when I met him. He is my savior, but...he is also my worst enemy.

A count’s daughter who scored hopelessly on the school's exam, Rururia Talbot!

I was talking to my best friend Sarah while eating my favorite tart, before I ran into a fight between the Crown Prince Christoph and Duke’s daughter, Irene.

The fantasy rom-com of a count's daughter who wants to return home peacefully begins!

When evil aliens arrive on Earth, seeking its destruction, it’s up to the planet’s kaiju monsters to save the day! But things aren’t exactly as you’d expect… These kaiju may be adorable young women, but they’re no less ready to kick some alien butt!

Lin Tian-Yu is the president of the student council and the disciplinary committee, and Xu Ze is a high school freshman. During a regular classroom inspection, Tian-Yu finds Xu Ze sleeping during morning self-study and reprimands him. Their seemingly ordinary encounter ends up changing the lives of the two greatly as they grow closer despite their apparent differences.

Saotome secretely loves Moe idols even though she is a gal(Japanese term for popular girls). Otonashi is what you would consider Otaku(nerd) that also has a secret.

A dormitory climbing school that consists of junior high and high schools in the mountains of N prefecture. There was another No. 1 in this school with the No. 1 advancement rate from the University of Tokyo. That is the highest crime rate in the school. Kotobuki, who is in charge of the school police, starts a detective activity in the name of Maboroshi Panty to help her father.

Makoto is suddenly confessed to by her narcissistic childhood friend Kikuchi Reita. Not even just any confession, he stands in the street and publicly says “If you want a boyfriend that badly, I don't mind going out with you”. Which was obviously a no, since Makoto has never considered Reita to be a man, especially a man of interest. What will become of her daily life now that Reita insists on her going out with him?

Middle-schooler Mayuki wants to enter Ohtomo high school to join her beloved senpai Akira. Problem is: her grades are so terrible there's no way she can make it into such a high level school.

Thus her mother hires a high school girl named Rin as a private teacher to help her daughter. Seeing how the girl looks so much more mature than her, Mayuki ends up asking Rin to teach her more than just school subjects…

Asuha wakes up to find herself naked in her childhood friend's room. On top of that, she's the size of a doll!

Marco, a boy who admires healers who support warriors and heals all. In order to make his dream come true, he enrolls in a nursing school, "San Castello," which specializes in training healers. However, when he entered the school, it was a world where females were 90% and males only 10%! And what's more, contrary to the fun school life he hoped for, this school has various courses which will put his own life at risk!
What fate will fall upon our plucky protagonist is...!? A little naughty struggle featuring the sweat and tears of a shota aiming to be a Healer!!!!

Exactly what the title implies.

Eishi Karasuma is a loner with a monotone life and his only friend is Mikisada Kamoda. One day they venture together while skipping class and they meet Tsubame, a very energetic girl, and Rei Sagisawa, a pretty boy that attends the same middle school. On their way back to school a sudden event happens. A mysterious boy with wings will come to help.

Leo, a common middle school student, was accidently invited to a Wechat group full of miracle figures, such as Lord of Thunder, Mother of Lighting, Mighty Miracle God... since then his life became totally different with wonderful equipment he got from the Wechat group.

Mizuki and Kazuya, childhood friends, are 3 years apart.
It's not really a so-called "Age Gap" but that makes some distance between them during their youth.
From their childhoold to the present, story will be told about these two who are 3 years apart.

Links:
Artist’s Pixiv: https://www.pixiv.net/member.php?id=596062
Artist’s Twitter: https://twitter.com/shimazakikazumi

From MangaHelpers:
Aku Maya is a demon, come to do some hands-on practice in the human world. She's living at a boarding house, attending school as a human girl, and keeping her demon nature secret from her close friends Sui, Sawa, and Arata. Maya's supposed to be increasing and collecting the negative energy of the humans around her with her 'evil checker' phone, but she doesn't seem to be able to take much pleasure in it. Besides that, what would her friends say if they found out she was a demon?

Lizia is reincarnated into an otome game world as a mob character.

She decides to live with two lives worth of filial piety, however, she has been betrothed to Bernhardt, the last villain in the prince' Route. This is the struggle of Lizia as she tries for a peaceful life.

Xiao Man, the beloved heir to the north area's martial arts club, suddenly decides to transfer to a south area high school to pursue "him". However, on her first day as a transfer student, everyone –including the teachers– mistakes her for a male delinquent. How will she get the boy she likes to see her as a love interest instead of a "buddy"? Adventure into the life of Xiao Man!

In a world where youkai and humans attend school together, a boy named Atsushi Fukuzumi falls for snow youkai Muku Shiroishi. Fukuzumi's passionate feelings melt Muku's heart...and the rest of her?! The first volume of an interspecies romantic comedy you're sure to fall head over heels for!!

Unoki-kun, a boy who's been bullied since elementary school, ends up becoming the exclusive errand boy of the top delinquent of his school, Toramaru-san, who told him "Be mine" right after entering high school. But the truth is that Toramaru-san meant it as a confession of love!! This is the beginning of a love misunderstanding between Toramaru-san who thinks she's in a relationship and the beta Unoki who think he's being bullied.

Collection of cute short stories focusing on formation of relationships.

1-2) Welfare Storm
A student has a crush on a new, beautiful, substitute school attendant. But the attendant is a jinker and brings unhappiness to the student...

3) Attraction Liqueur
A young ace worker from tech sector becomes the assistant of an ace salesman who cannot drink too much. The young worker shows how much he has yearned for the salesman and invites him to their private drinking session...

4) Hibinoya Boarding House Chronicle
The cloistered son of noble family suddenly lives to the hero's house in order to learn the life of ordinary people...

5-6) Fickle Wings & Everyday Fickle
Yoshimoto Oki is a quiet boy. With both his parents working overseas, he is often home alone, and so finds solace in his computer. But when he participates in and wins the "Infinite Colour Wing" game contest, the prize turns out to be something more than he bargained for...