I, Hayato, once met an Oni princess when I was young, and I made a promise to marry her when I became eighteen. But after that day, I was predisposed to experiencing ecchi disasters whenever I touch women. With the cause unknown, I intended to live out my life in high school without ever finding a girlfriend. But on that faithful day, Sakura, the Oni princess grown up, came back as promised.

This is the tale of an Oni Princess x High School Boy and the mystery of the ecchi Curse Charm that circles them.

In the Kokoro series:

Vol.1 - Otokogokoro (A Man's Heart)

1 & 2. Otokogokoro & Otonagokoro
Salary man Saki almost makes it home but passes out from fever just as college student Shinomiya passes by. When Saki comes to he realizes he's in a strange apartment and Shinomiya has been taking care of him for the past two days! Not wanting to be indebted, Saki tries to repay him as thanks but Shinomiya's having nothing of it. Luckily, Saki's pretty creative when coming up with a way to express his gratitude that has them both wanting more...

3-4. Kiss Kiss Kiss

5. Nibukoi (Dull Love)

6. Hiiragi-senpai no Koi no Ohanashi

7. W Pure

Vol.2 - Koibitogokoro (Heart of Lover)

Vol.3 - Koigokoro (Heart of Love)

Vol.4 - Tokimekigokoro (Heart of Excitement)

The number of chapters comprising the main story in each book is as follows:
Otokogokoro (2 chapters),
Koibitogokoro (6 chapters + omake) entire book,
Koigokoro (2 chapters + omake), and
Tokimekigokoro (5 chapters + extras) entire book.

From Del Rey:
Every letter the mailman delivers brings a new chance at love. With wit, humor, and mystery George Asakura leads us through a series of brief tales of affection, rejection, miscommunication, and connection that are sure to charm the romantic inside you.

A Perfect Day for Love Letters received the 29th Kodansha Manga Award for shoujo manga in 2005 (shared with Oi Piitan!!).

From BLU:
Get ready for hot tea and hotter action in this tale of opposites attracting on the tatami mats. Poor Tokumaru Madoka is just a regular energetic guy that can't seem to go even five minutes without breaking something. One day his hapless sister has had enough, and she forces him to join their high school’s Tea Ceremony Club, hoping to instill a little discipline in her hopeless klutz of a brother. Tea Ceremony Club president Hasune Kazuma is Tokumaru’s complete opposite. The tall, dark president is the pinnacle of restraint, having been taught from a young age how to uphold his family’s traditions. The sophisticated president and his awkward pupil conceal a brewing attraction, but they can’t avoid steaming each other up. But even full to the brim with passion, will the two of them be able to bridge their differences and get along with each other?

From Decadence:

This manga is a love comedy collection of oneshots about how mysterious meetings can lead to falling in love before you even realize it! These stories will be sure to make laugh and cry at times.

Volume One includes...
-The mysterious NEET owner who appears every evening from the floor above.
-The husband who struggles to support the love that has come to visit his wife
-The strange businessman who has purchased a gravestone for his final resting place?!
-The little brother who suddenly appeared in the room of someone living alone...

When Senjou Taki was harshly raped by the neighboring territory's feudal lord, Kazusa Toma, all he could only think of was his loyal servant, Somei Chikage.

In the Kokoro series:

Vol.1 - Otokogokoro (A Man's Heart)

1 & 2. Otokogokoro & Otonagokoro
Salary man Saki almost makes it home but passes out from fever just as college student Shinomiya passes by. When Saki comes to he realizes he's in a strange apartment and Shinomiya has been taking care of him for the past two days! Not wanting to be indebted, Saki tries to repay him as thanks but Shinomiya's having nothing of it. Luckily, Saki's pretty creative when coming up with a way to express his gratitude that has them both wanting more...

3-4. Kiss Kiss Kiss

5. Nibukoi (Dull Love)

6. Hiiragi-senpai no Koi no Ohanashi

7. W Pure

Vol.2 - Koibitogokoro (Heart of Lover)

Vol.3 - Koigokoro (Heart of Love)

Vol.4 - Tokimekigokoro (Heart of Excitement)

The number of chapters comprising the main story in each book is as follows:
Otokogokoro (2 chapters),
Koibitogokoro (6 chapters + omake) entire book,
Koigokoro (2 chapters + omake), and
Tokimekigokoro (5 chapters + extras) entire book.

Nine years ago, while on holiday, Nonozumi Kanata received her first kiss from a boy named Haruka. Now age 15, Kanata has continued to love him and treasures a photograph of them together, which she always carries with her. Finding that she will be spending the Summer Holidays alone, she decides to find Haruka using the address on the photograph as her only clue. As she has never travelled alone before, she nearly boards the wrong train, only to be "saved" by Kasukabe Kairi--a very cute and popular boy from another class at her school. As they travel, she tells Kairi of her dream and he decides to help her in her search! Will Kanata be successful in finding the true "Haruka"? And when she does, will he return her feelings? And what about Kairi who's been helping and protecting Kanata on her journey? The path to true love is never easy.

From Chibi Manga:

Ritsuka and Kaze-kun are currently lovey dovey, but Aizawa-sensei who is extremely beautiful and has the perfect body just started working. Is Kaze-kun also excited over sensei’s enormous breasts? With the appearance of a rival, Ritsuka is in a bind!
I want to be my prettiest when I am in senpai’s field of vision…
Hayashi, Ritsuka’s friend is the main character in the extra story. This is an extremely happy compilation volume to the Koigokoro series!!

A story about Kawai-san taking music classes to be together with the senpai she loves. The problem is that her life is made unbearable by the sullen and strict drummer Ichibashi-san.

From Enchantment Scans and Fate:

There are seven love charms that are circulated at Ayase Academy. Trusting those, Ritsuka believes that she will have a wonderful boyfriend. However, Kuze-kun, who's super scary and infamous at school, keeps getting in her way... Will Ritsuka find the love of her destiny?!

From Shoujo Crusade:

Ako is afraid of boys because of an incident from her past. But will a boy she meets by chance be able to change her?

Tooru and Katsuyori story adapted from Inu Koi Series.

From Cidsa's Scanlations On the first day of school, Tamura Masafumi sees Seiwa Narumi and immediately passes out. It is discovered that when Tamura was a kid he had psychic dreams and could predict many events. He thought they had all disappeared but at the beginning of Junior High he has another one, and it shows him having sex with another man! Tamura refuses to become gay and swears to prevent it. When he sees Seiwa, he realizes that this is the other man in his (now frequent) dreams! So Tamura treats Seiwa quite badly in hopes that he will leave him alone, however, Seiwa has other plans. What will happen between these two? There are several side stories in the anthology Aruji no Oose no Mama ni.

From Angelic Powder:
The princess of love, Koiko is given the power to zap people to admire her but the power will leave her when she reaches adulthood and marries. There was one boy she had never zapped before, Shirou. But he turns out to be someone different when he doesn't show up as he promised. Koiko being heartbroken runs to find him, only to find new things she never knew about him. It turns out he is one of the legendary shadow ninjas.

The story follows a girl named Mame, whose family runs a public bath. She has held on to feelings of unrequited love for her childhood friend for twenty years.

(Kiss comes out twice a month, but Koiiji is published only in every other issue.)

Omoigabuchi, a pond with a legend attached: "If two people go in together, they will be bound to each other for life."

The story of three couples who get dragged into this love pond.

Mone's motives for joining the art club might not be pure but her heart is.

Based on the original song Love-colored Ward by OSTER project, One late night, Miku gets a text from a classmate of hers, saying he’s down with a 38.5*C fever and asks for her help. What should Miku do? Obviously, 38.5 is not much of a fever so why should she even bother worrying? It’d be better to simply ignore it, right? Nevertheless, for some reason, she just has to go see him. Could this be…love?!

From Girls' Generation Scanlations:

He's perverted, malicious, a devil that calls himself 'Ore-sama'.
His true character is -? The Demon King, Char, from a parallel world called Avalon, fell in love with the daughter of a shrine, Hashiba Rin. Both their hearts and bodies have been entrusted to each other, but a first love, Shou-chan, confesses to Rin-?

From Starry Heaven:

Hashiba Rin, the daughter of a Shinto shrine, fell in love with the demon king, Char, who came from a different world called Avalon. They shared their love with their body and mind, but Rin's first love, Shou-chan, confessed to her and---?
Following Char and Rin's meeting, "Honey Colored Devil," the popular serialized in heaven love magazine appears with an extra chapter<3

from Renta!