The characters in this list don't necessarily need to be matriculated in college. Whether a young adult has just left home to attend college or to start full-time work, she will usually be dealing with the same issues: "What do I really want to do with my life?", "Am I on the right path?", "This microwaved dinner tastes terrible...", and other such coming-of-age questions. (Take that with a grain of salt- I'm assuming this based on my own limited experiences. ^^;) So, basically, characters who are definitely in the "traditional student" college age range and/or in college- e.g. a 23-24 year-old college senior who took a year or two to pass the college exams, or an 18-19 year-old studying to pass the entrance exams, could count.
Maria-sama ga Miteru (seasons 2-4)- Sei, Youko, and Eriko reappear a few times after they graduate, with Sei majoring in Comparative lit at Lillian women's university (yay, women's colleges! ^^ It's extra-cool to me since I attend a women's college.), Eriko attending a different university to study the fine arts (...I think...correct me if I'm wrong), and Youko studying law at another university.
Kanamemo- ... -_-; Four out of six of the main characters are college-aged women, with Yume attending a patisserie academy to become a chef, Hinata studying to pass her college exams, Yuuki not doing anything besides working for the newspaper, as far as I saw, and Haruka studying bio-fermentation...to make beer on demand, I guess. I've already explained why, despite having a cute yuri couple, this series leaves a horrible taste in my mouth.
I need more to work with here… come on, animation companies! (Idea: Forget Hanadera. We need a Marimite spin-off about Sei attending Lillian university, where she is eventually joined by Sachiko who pines for her beloved Yumi, until Yumi graduates and enrolls in Lillian university and becomes entangled in a love square with Sachiko, Sei, and a jealous Kei!! XD
Published in English:
Rica'tte Kanji!? by Rica Takashima- A cute slice-of-life comedy about Rica, a young woman studying education at a women's college in Tokyo, and Miho, her girlfriend who's studying the fine arts.
Maka-Maka by Kishi Torajiro- A manga about two friends, Jun and Nene, who both attend college and have boyfriends, but still have sex with each other. I tried this one after hearing all the hype about it, but didn't care for it much, quite honestly…
Works by Eriko Tadeno- I got this one after liking what I saw of Tadeno's work on Yurizuki and in Yuri Monogatari. Works is a collection of Ladies Comics stories that all focus on adults, with one story ("I Like You The Way You Are") focusing on two women in college who were once had a sempai-kouhai relationship in high school. I normally don't go for manga this explicit- call me a prude-, but I like these stories since they don't focus on the adult material (one story is completely clean) and include middle-aged (!) yuri characters, which are about as common as snow in the Caribbean.
Manga not published in English (btw, if you enjoy any of these titles via scanlation, you should really support the artist who made them by buying them so that they can continue to create good yuri):
Love My Life by Yamaji Ebine- A slice-of-life drama about Ichiko, a college student who comes out to her dad, which causes him to tell her that he's gay, as well as her (now deceased) mother. Ichiko has a girlfriend named Eri, another student who's studying to become a lawyer.
Free Soul by Yamaji Ebine- Another slice-of-life drama about an aspiring mangaka named Keito who draws yuri manga while working at a record store. She falls in love with and tries to win the heart of a jazz musician named Niki.
Kawaii Anata by Hiyori Otsu- A collection of one-shots, my favorite being “Maple Love”, which is about how two college students become a couple. (A shout out of thanks to Nakayo for suggesting this one! ^^)
Octave by Haru Akiyama- An ongoing multi-volume series about an assistant manager working at a talent agency and a song composer (both former idols) who fall in love.
Claudine by Riyoko Ikeda- A little known 1 volume manga by Ikeda, about a transgendered man (a man in a woman’s body- although some people might debate whether Claudine is FtM or not) who falls in love with several women who return his affections (for a while, at least). Well-done, but it has a sad ending. (Read Honey & Honey for a better/non-depressing story that includes FtM characters. ^^)
"Hands Off My Girl" by Minami Q-ta- A one-shot about how jealousy brings two college students together. I must admit that I’m not a fan of Minami Q-ta’s work, even though it’s...well… different, and worth checking out.
Moonlight Flowers by Mutsumi Tsukumo: The second part of the book, “Midnight Flowers”, follows Kaoru realizing her sexual identity in college, while also learning about a relationship between her boyfriend’s stepmother and her “special friend” (Oh, snap.) who runs an art gallery.
That’s all that I can think of for now. Feel free to suggest any I’ve missed! :)
Added on 08/14/2009 (Many thanks to Erin for suggesting these titles! ^^):
"For You, My Beloved" by Nagi Yoshizaki and Aya Sasaki: A sweet one-shot about two women attending a nursing school in the country.
Honey & Honey by Sachiko Takeuchi: A slice-of-life manga about Sachiko, a college student, and her girlfriend Masako (not sure whether she's a college student ^^;), that strives to provide a humorously realistic look at lgbtq life in Japan.
"Instinct and a Chromosome" by Haruko Okai and Maiko Akiyama: A one-shot about a woman attending business school and the woman who she falls in love with there, along with the obstacles they face before they can have a happy (?) ending. I didn't care for this one either, quite honestly, although it's worth checking out for fans of josei yuri.
"Soft-Boiled Fujoshi" by Akiko Morishima: A one-shot published in Yuri Hime magazine about Chie, the older sister of one of the protagonists of Morishima's Hanjuku Joshi- who happens to be a raving otaku. XD This one-shot follows her quest to experience yuri "moe", but in the process she winds up finding love with another girl otaku. :)
Ruriiro no Yume by Akiko Morshima: This Yuri Hime collection (coming out on July 18!), which will include numerous adult yuri characters (score! ^^), will contain a one-shot titled "Princess of the Stars" (published in issue 11 of Yuri Hime) that contains college-aged characters; I haven't read this story yet since I don't own issue 11 of Yuri Hime, but I'm sure that it's excellent.
Love Vibes by Erica Sakurazawa: The protagonist, Mako, is a college student (admittedly, one who doesn't seem to take her studies very seriously) who finds love with Mika, another young woman around her age. This story is very well-done, although I can't say that I really like any of the characters much. <-- Edit on 11/01/2010: Wtf. No. Read this.
"P=NP?" by Amaguri Taroh: A one-shot published in issue 1 of Phryne (a lesbian magazine), about a college student who isn't sure about whether her girlfriend really likes her, or just wants her to do her homework.
"A Cruel God" by Youko Takano and Toko Shouya: Another one-shot from issue 1 of Phryne, about a 20 year-old OL who falls for a woman at the gym she belongs to (although not for any reason I can really understand...but hey, whatever floats her boat) and later sees her at a lesbian bar.
"Sweet Exercise" by Amano Shuninta: A one-shot in issue 3 of Yuri Hime Wildrose; it hasn't been scanlated yet, but it should be out soon.
"Traces of Snow" by Mako Takahashi: A one-shot in issue 1 of Sayuri-hime (a special mini-edition of Yuri Hime magazine) about a woman who receives a visit from a friend she was once (and probably still is) in love with.
Added on 08/20/2009:
Double House by Nanae Haruno: An excellent story about a transgender woman named Maho who saves and befriends a woman named Fujiko who falls in love with her. Fujiko is taking a break from college to raise money so that she can attend school again.
Pieta by NanaeHaruno: Also excellent, about two classmates, Sahoko and Rio, who become friends despite Rio having numerous issues and Sahoko seeming to have everything together. Saying too much would constitute a spoiler, but this title belongs on this list.