Onozucca Kahori's name may sound familiar-- she did a one-shot for the first issue of Yuri Shimai. That one-shot is available scanlated at Lililicious; it's called "Pure Shadow." To my knowledge, she hasn't done any other work for Yuri Shimai/Hime.
Nico Says is a collection of one-shots. The yuri one-shot, "Dessin" (a French loanword written "dessan" in Japanese and used to mean "sketch" or "rough drawing"), is a pretty run-of-the-mill unrequited love story-- girl A is in love with girl B, girl A and B get drunk and sleep together, girl B brushes off girl A because she's in love with (or, at the very least, going out with) boy A, girl A is crushed but has more knowledge of her own sexuality by the end.
As you might imagine, this one-shot also involves art-- girl A (whose name is Ikenaga) and girl B (Fujino) both belong to their school's art club, and Ikenaga's self-portraits are used as a reflection of how her self-image changes from the beginning to the end of the story. Ikenaga also has a male classmate/friend, Miyamoto, who plays a big role in the story.
Click the thumbnails for the full-size scans.
Ikenaga thinks to herself that she wants to do everything she can for Fujino right now, since she'll have to worry about entrance exams next year. Fujino is the one with the long hair.
Fujino is being bullied, and Ikenaga saves her. As they're talking afterwards, Ikenaga tells Fujino she's pretty. Fujino, surprised, tells her that's the first time another girl has praised her that way.
In the narration, Ikenaga tells us that she and Fujino begin to grow closer; Ikenaga quits the basketball club and begins spending more time with Ikenaga in the art room.
Fujino invited Ikenaga over for dinner one day. They both drink, and Fujino seems to get pretty drunk-- she wants to sleep out on the couch, but Ikenaga tells her she should sleep in bed so she doesn't catch a cold. Fujino insists that Ikenaga sleep with her in the bed, because it's cold.
As they're lying in bed together, Ikenaga reflects on being in bed with Fujino, thinking that she's able to be there because she's a girl. Then she kisses Fujino. Fujino seems surprised/upset at first, but then she kisses Ikenaga back, and things escalate from there.
Later, Fujino is out sick from school and Ikenaga goes to see her, bringing her notes. Ikenaga thinks to herself that she feels kind of weird seeing Fujino after what happened between them, but she's glad she came. She also thinks to herself that sleeping with Fujino made her feelings for her grow. She tries to touch Fujino's hair, but Fujino brushes her off, telling her she's tired. Ikenaga apologizes.
Just then, the doorbell rings-- Fujino's boyfriend has come to see her. Fujino's face brightens as soon as she sees him, and that upsets Ikenaga.
Ikenaga thinks about the differences between men and women, and wonders why men have a natural right to embrace women but women don't-- are they really so much better than women? She thinks to herself that her feelings for Fujino are definitely stronger than Fujino's boyfriend's are.
She wonders if Fujino wants her to forget about what happened between them. She doesn't think that's fair.
Ikenaga kisses Miyamoto (who, by the way, has already guessed at Ikenaga's feelings for Fujino and asked her about it), just to see what it's like; it seems from this scene that Miyamoto has feelings for Ikenaga, though he never says so straight out. Ikenaga apologizes, and Miyamoto leaves.
Ikenaga reflects on the kiss-- it wasn't anything special, nothing like the ones she shared with Fujino. She wonders why all the other girls get so excited about guys.
Ikenaga confronts Fujino, asking her feelings on what happened between them. They're in a crowded hallway, and Fujino doesn't want to talk about it in public, but Ikenaga keeps pushing, asking what she is to Fujino. Fujino tells her that she was just fooling around, and Ikenaga slaps her. She feels ridiculous now.
Fujino's boyfriend appears and asks her what happened to her face. Fujino tells him it was nothing, and asks him to kiss her-- right in front of Ikenaga.
Ikenaga and Miyamoto talk about what just happened, and he comforts her as she sobs.
A while later, Ikenaga receives a letter from Fujino explaining that Fujino had a fight with her boyfriend before that night she spent with Ikenaga, and that she was lonely because of it-- he was her sole support, and fighting with him meant she lost that source of support, so it was a really rough time for her. This makes the situation a little easier to digest for Ikenaga, though she can't just forget it ever happened.
Fujino quits the art club, and Ikenaga considers quitting too, but she's told she can't quit the club until she finishes the piece she's working on.
Ikenaga shows Miyamoto the self-portrait she's working on, and he comments that it really looks like a girl this time (he saw one she was doing at the very beginning of the story, and it looked like a guy).
At the very end of the story, Ikenaga wonders to herself if she'll ever be able to fall in love again; then the manga ends with the symbolic phrase "Spring is coming."