I love math. Just after the high-school entrance ceremony, I meet a beautiful girl: Milka. Milka is a mathematical genius. She shows me many math and many elegant solutions. Milka and I spend a long time discussing math in the school library.

One year later, I meet another mathematical girl: Tetra. Tetra is one year younger than me, and asks me to teach her math. While I teach her, she begins to understand math and gradually to love its elegance.

The third series is about logic puzzles, Peano arithmetic, epsilon-delta, Cantor's diagonal argument, Hilbert's program and Gödel's Incompleteness Theorems.

A story about a maid with animal ears and her mistress.

The story revolves around Tsunashi, the child of royalty who was left behind in the lost kingdom of Karan. He is expected by those around him to awaken his great powers that sleep within him in order to revive the kingdom — but rather than fighting, Tsunan enjoys playing in the world of books. However, he must become serious soon, as a new army is threatening to invade Karan.

From MangaHelpers:
Yasaka Tokiwa lives in an unusual time, and according to his dreams, it's about to become even stranger. He's been having a dream of a woman called Ri'in ever since the robot, who he calls Makina, came to his home. He and Makina attend the same school, where their other classmates include a secret ninja (Kusanagi Kanata) and a sorcerer (Yata Haruka).
When Tokiwa, the robot, the ninja, and the sorcerer rush to rescue the student council president from a demon, the boys find that they've all been having the same dream! What is going to happen to their world?

At a boarding girls' high school where every student is an assassin, they target only one life: "The Hare", who appears to be a girl named Ichinose Hare. Similarly, "Azuma Tokaku" is an assassin who transferred schools to target her, however she gradually became attracted to "Hare" and decided to protect her.

Extreme school life START!

Inuyashiki has a family, a wife and two kids, none of which care about him. When he learns that he has only three months to live he realizes that the only one who will miss him is his dog. Shortly after this realization he is killed in a crash landing by aliens. He is rebuilt by them as a machine with a human exterior. How will his life change now that he isn't human.

This is a manga with several oneshots.

Story 1: Pure Love Strip
Story 2: Beautiful Beast
Story 3: Morning Waking Kiss

Story 4: Daisy by AMANE Yuko

Story 5: Lustful Darling
Story 6: Love Princess and W Prince
Story 7: Yokujyou Nyan Nyan (Alluring Nyan Nyan)

Who do you think lives next door? A college student?
A secretary? A foodie? A quiet sort?
Or a killer?

Humanity's peaceful days all at once transform into an unspeakably odious hell.
The sudden invasion of wasp-like insects, along with gargantuan "dolls" wielding their enormous alien weapons, annihilating everyone in their path.
In the middle of the chaos, high school first-year, Iruma Ikaruga, fights to save his best friend and his beloved senpai from the dolls' assault with an unyielding spirit.
However, all that awaits him is despair.
Just what are the enormous puppets known as "Dolly"after?
What fate awaits Iruma?
The curtain has risen on humanity's "puppet show" of unimaginable despair, and the battle for survival has begun.

From: Easy Going Scans

A continuation of Brave 10. The main protagonist is an Iga ninja named Saizou, who meets an Izumo priestess and protects her on her short journey to Sanada Yukimura. Sanada Yukimura is a powerful warlord in the Sengoku era. Sanada wants to gather 10 warriors, a party unrivaled in skill and power, to set his still secret plan into action.

A little bit made up and a lot of it not.

A world where logic does not exist and anything is possible. The only limit is your imagination. Bite-sized comics with dry humor for the broken souls.

Marriage is in shambles. But still their pride stops them from seeking each other. Thats when both drift out to get the taste of some 'Drugcandy' (adultery). A tale of two people exploring out of their relationship.

Fuyune hates Christmas because it only brings loneliness. But will this Christmas be different?

Jang-Mi and Taebong's long-time friendship is put to the test after they both sleep together for one night. Is this love or just sex? Read H-mate ( Hメイト, H메이트) by Turtle Feet now!!

Maybe you'll like: 
+ Brawling Go Manga
+ Skill of Lure
+ Sweet Guy
+ H Campus
+ Yahalue
+ A World That I Rule

From Kodansha:

Class troublemaker Ryu Yamada is already having a bad day when he stumbles down a staircase along with star student Urara Shiraishi. When he wakes up, he realizes they have switched bodies—and that Ryu has the power to trade places with anyone just by kissing them! After figuring out the workings behind this new and amazing ability, Ryu and Urara take full advantage of the situation to improve their lives. But with such an oddly amazing power, just how long will Ryu and Urara be able to keep their secret under wraps?

Yuki Anno just turned into a high school student, she's very nervous and what's worse, she is in a different class from her best friend Jiu. But she resolves to make new friends. Upon meeting Jiu's cousin, Yuki, who has the same name as her, will she be able to open up and show people who she really is?

N/A

From Yaoi Is Life:

Saichi and Kotetsu are drawing manga as a team while living in extreme poverty. At loss for an idea, both of them decided to write a “real BL” based on themselves! They rise to be a star in the BL world, but…?!

"The other short stories within explore a schoolboy crush that turns into something more, an antagonistic relationship between a wealthy heir and his crush, and the love life of Usaki, the editor of Saichi and Kotetsu’s stories" (June).