This series of manga is about a romance between the dimunitive Shingo and his friend Kumiko in different stages of their lives, from childhood to adulthood. It spans six different manga titles - 5 one-shot manga and a 10 volume 6th series that eventually wraps things up. It's well worth the time:

1. 130 cm no Dandy
2. Dodgeball wo Shiyou
3. Mirai Yousouzu
4. Step Up
5. Paris de Issho ni
6. Otona ni Naru Houhou (10 volumes) How to Become an Adult

Tomo is a highschool girl who lives in a town by a beach. One day she gets harassed on a bus, but is rescued by one of her classmates. Afterwards, he drops his keys, and the key ring has the same stone as one given to Tomo by a boy during her childhood. Is he the same person? Tomo believes the sea can bestow treasures on people, and she may about to be proven right in ways she couldn't imagine.
(Source: Tokyopop)

Taiko and her friends Haruka and Someko are the only members of their high school's "tea club." (English, not Japanese, tea.) One night they are drinking tea by moonlight and diminutive princes Assam and Earl Grey emerge from their teacups. They can't return to their Tea Kingdom until Taiko and Haruka make three wishes each, but the pair are reluctant to wish foolishly, which leads to the Princes of Tea hanging around the human world for a while. Various hijinks ensue, and more about the history of the Princes is revealed until there is enough drama to choke a teakettle with.

From Ochibichan:
Perky Yaoya is a first year student at Koushinmaru High School and a new member of the school newspaper staff. In order to become a full member of the staff she must uncover the identities of the Sannin Kichisa, a mysterious trio of masked avengers haunting the school!

A romantic comedy with a distinctly Japanese flavor. Next-door neighbors Chiro and Ritsu have been best friends since childhood. Ritsu, the eldest son of a family of traditional nichibu dancers, is thrust into the public eye as his career takes off, and his growing fame begins to test the pair’s friendship. And now the twist: when a wish made at a shrine actually comes true, Chiro and Ritsu find themselves inhabiting each others’ bodies. A further complication arises because Ritsu is not just a dancer, he is a famous onnagata, or female impersonator, popularly known as the “Courtesan Prince.” (Source: Mangafox)