Yume no Shiro is a one volume work by Masami Tsuda and consists of 3 short stories. Masami Tsuda is famous for Kareshi Kanojo no Jijou, or KareKano for short. These stories were drawn while KareKano was still running so the artwork is quite nice.
It's all about love couples. Also, there is a thread running through all three stories. That's a magician who helps the people. Who are the people he helps?
1) Inside the Forest
2) I'm a Mermaid
3) The Castle of Dreams
[Source: Baka-Updates Manga]

Yukino Miyazawa is the perfect model student. Pretty, kind, good at sports, always at the top of her class. But she's not all that she seems. It's all an act of deception; she is really the self-confessed 'queen of vanity,' and her only goal in life is winning the praise and admiration of everyone around her.

When she enters high school, she finally meets her match: Soichiro Arima, a handsome, athletic, popular, and very intelligent young boy. Ever since he stole the top seat in the class from her, Yukino has hated him, and has been plotting on how to take back her former place as the object of all other students' admiration.

What she wasn't expecting, however, was that Soichiro, the very boy she hated, would confess his love for her. Or that he would find out about her deception - and use it to blackmail her!

See the deep emotional story unfold as you walk through their entire high school life with this very real world pair and their group of interesting friends.
Together, they discover that they have more in common than they knew, and they slowly begin to bring out each other's inner selves.

* Also included are the following short stories in this manga:

? The Tiger and the Chameleon - A Promise
for One Week (Vol. 1)

? Ashita Mata Mori de Aoune (Meet Me Again Tomorrow in the Forest; Vol. 4) -
Always an outcast because of her black hair the heroine of the story finds a strange man in the forest - a man from Earth - and he has black hair, too!

By the mangaka of Kare Kano comes a new historical comedy. The comedy story is set in an ultra-prestigious middle school at the height of Edo-era Tokyo, over 150 years ago. It centers around a son of the ruling Tokugawa clan's Mito family and a daughter of an elite Tokugawa shogun.
(Source: Mangahelpers)

The "ancient fantasy" series will feature a girl with mysterious powers from the "legendary age of shrine maidens" whose meeting with a boy changes her life.
(Source: ANN)

Eensy-weensy Monster is about a girl, Nanoha, who spends an ordinary school life with two merry close friends, reuniting with Hazuki, an archrival from grade school. From her anger, a mysterious monster appears!