Yamada is an ordinary girl who isn't particularly popular, smart, or pretty. One day, when she's watering the plants beside the track team's practice area, sports star Kase passes by and shares a cheerful word. From that day on, Yamada is besotted with her, and watches her crush from afar. Before long, they meet again and Kase ends up saving her from an embarrassing situation. Then, when she glances at Kase in the changing rooms, and sees Kase watching her, she can only blush and look away.
So begins a gently-paced story exploring the relationship between the two girls: whilst Yamada doesn't understand why she has such feelings for another girl, she knows that, more than anything, she wants Kase to be in love with her.
She'll have to wait a little longer, though. Soon after, Kase strikes up a conversation, expressing a desire to see her over the Summer break. During the holidays and the following term, Kase and Yamada continue to meet. As their friendship deepens, they tentatively and shyly explore the idea of being more.
Kase-san (or Asagao to Kase-san —Kase-san and Morning Glories—) is a W.A.F.F.-style Yuri Genre manga by Takashima Hiromi that began as a one-shot in 2012, but turned into a multi-volume series, which came to a close in March 2017. Seven Seas Entertainment is releasing the series in English.
The Sequel Series, titled Yamada and Kase-san, began in April 2017 and follows the title characters' new college life in Tokyo.
An official short animation has also been produced and can be legally seen here.
An official hour-long OVA animated by Zexcs began premiering in Japanese theaters on June 9th, 2018.
Kase-san contains examples of:
- The Ace: Kase, for the girl's track-and-field club. She can even outrun the members of the boy's team, when worried by Yamada that is.
- Adorkable: Both girls, but Kase in particular is a good example, as she seems really confident and cool from the outside, but can be reduced to a blushing mess just from Yamada getting too close to her.
- Afraid of Blood: Mika. Although she wants to comfort Yamada, she can't bear to look at her while she's bloodied up after being stampeded at the marathon.
- All of the Other Reindeer: Downplayed—the other girls often make fun of Yamada for being dumb, but the manga never really takes it beyond dispiriting bullying.
- Averted in the sequel series, the students at Yamada's college are impressed with her gardening talents, and even give her presents.
- Alternate Continuity: The bonus Chocolate and Kase-san seems to assume a different ending to the marathon, as it starts with Yamada writing a love letter to Kase thanking her for her help, but they're not dating. Mika also doesn't seem to be aware that Yamada likes Kase, even though in the manga she implies she'd been guessing that for a while.
- Anger Born of Worry: Shortly after the marathon begins, Yamada is trampled by a group of boys and ends up bloody and bruised in the school infirmary. From the window, she can see Kase, and yells out at her to not give up, which causes Kase to suddenly speed up drastically—and then, minutes later, appear at the door, yelling about Yamada's injuries.
- Beware the Nice Ones: Kase is friendly, sensitive, and extremely humble despite being popular and a star athlete. But she won't tolerate any mistreatment of Yamada for a second, and will aggressively confront anyone and everyone who does so.
- Big Damn Heroes: When Yamada's getting harassed by a group of drunk old men, Kase slams her foot into the chairs they're leaning on and furiously reprimands them for their inappropriate behaviour.
- Boyish Short Hair: Kase.
- Brick Joke: In the first chapter of the sequel series, Yamada is once again trampled over by a group of boys, the rugby club this time.
- Butch Lesbian: Kase.
- Cannot Spit It Out: Kase manages it eventually, though.
- Chocolate of Romance: Chocolate and Kase-san revolves around Yamada trying to give home-made chocolate to Kase but being held back by her nervousness and jealousy that Kase already has so many admirers.
- Comic-Book Time: Lampshaded in one omake. The story had been going on for five years despite far less time passing in-story, but the technology kept getting updated to reflect the real world. Yamada is surprised to learn her flip phone has gone out of style and that Kase now uses an iPhone.
- In the sequel series, Yamada has now upgraded to an iPhone.
- Covert Pervert: Despite both being far too awkward to make a move on their desires, it's pretty clear that both Kase and Yamada are attracted to one another.
- Crush Blush: Yamada very often, and occasionally Kase, too.
- Distracted by the Sexy: At one point when Kase corners Yamada to make her explain why she's been ignoring her, Yamada has to look away because Kase's boobs are directly in front of her face. A couple of pages later, Kase can't help but watch Yamada's skirt as she awkwardly tries to mount the bike.
- "Do It Yourself" Theme Tune: The ending song in the OVA is sung by Kase and Yamada's seiyuus.
- Don't Look at Me!: Kase says this at one point when she doesn't want Yamada to see her cry.
- Embarrassing Last Name: Yamada. She says it makes her sound like a potato. As a very common name that literally translates to 'mountain field', that's probably not too big an overreaction.
- Even the Girls Want Her: Kase is quite popular, and receives a huge heap of chocolates every Valentine's.
- First Kiss: At the end of the first volume.
- First-Name Basis: Kase starts calling Yamada by her first name, Yui. Kase then asks Yamada to call her by her first name, Tomoka, as well. Yamada promises that while she's not used to first names yet, she'll get the hang of it.
- The girls are still feeling awkward about this in the sequel series. Kase has even gone back to using "Yamada" to make the latter more comfortable.
- Gayngst: Also downplayed—Yamada worries that since Kase's a girl, they can't be together, but it never gets hugely dramatic.
- Genki Girl: Yamada's friend, Mika.
- Green-Eyed Monster: In the second chapter Yamada briefly gets jealous after Mika tells her that one of Kase's ex-girlfriends is in the track and field club with her, and is occasionally jealous generally of all of Kase's friends. This becomes a significant plot point later on when Yamada sees Kase hanging out with her and starts to feel more insecure about it. As it turns out, Kase never had a girlfriend before Yamada, and she and the other girl were only friends.
- Green Thumb: Yamada puts a lot of effort and love into the school's flowers.
- In the sequel, she now looks after her own flowers at her college, she even attends those that belong to her fellow students. They don't mind it at all.
- Hair of Gold, Heart of Gold: Yamada is incredibly sweet and is able to see the good in all kinds of things most people can't.
- I Didn't Mean to Turn You On: Both girls for one another. At least on Kase's end, it's partially deliberate, but she can get it just as bad from Yamada.
- Improbably Female Cast: The manga technically takes place in a mixed-gender school, but we almost never see any males. Amusingly enough, when they do appear, they're usually drawn with lenny faces (presumably to emphasize how Yamada sees Kase as far cooler than any of the boys).
- Indirect Kiss: At one point in the story, Kase offers to share her water bottle. Yamada convinces herself that since they're both girls it isn't a big deal, but once she's taken a sip Kase takes the bottle and puts her mouth right over it in a huge gulp and gives Yamada a deliberate glance.
- The Ingenue: Yamada is so innocent, she doesn't realize what a love hotel is, nor does she know that two girls in a relationship can also have sex. This simultaneously amuses and frustrates Kase, who clearly is suppressing some desires because of it.
- Insecure Love Interest: Almost every other chapter has Yamada worrying over how popular and accomplished Kase is, and how dull she thinks she is in comparison. Interestingly enough, Kase seems to be just as insecure, believing she might be coming on too strong and often afraid that Yamada will break up with her for it.
- Ends up becoming a major issue at times when Yamada, out of fear for being a nuisance, sometimes fails to properly communicate her doubts to Kase. This results in Kase believing herself to have done something wrong, driving her into a desperate panic as she jumps to incorrect conclusions about why Yamada is sad or avoiding her.
- Last-Name Basis: Both girls with one another, even after they start dating. It's probably because they got used to calling each other that way and stopped thinking about it. For the record, their full names are Tomoko Kase and Yui Yamada.
- Lovable Jock: Kase is so athletic, she even gets better times than all of her seniors. However, she's a really nice girl and, while confident, never acts superior.
- Love You and Everybody: Yamada is really excited when Kase invites her to a track meet, but is quite disappointed when she realises that Kase invited lots of people.
- Mundane Made Awesome: Yamada can get very fired up over plants.
- Panty Shot: The first time Kase saw Yamada, she was bending over to care for some flowers. Kase covertly ducks her head to see if she can see anything.
- Reality Ensues: The first chapter of the sequel series quickly establishes that both girls barely get to see one another until the weekends, due to them studying at different campuses.
- Retcon: In the original magazine version, after Yamada and Kase kiss, Kase asks Yamada for a different request, but then says she'll tell her after the tournament, and the chapter ends. In the book version, Kase instead asks to go out with Yamada, who agrees.
- Romantic Wing Man: Yamada's best friend Mikawa is often exasperated by her antics, but does her best to support her relationship with Kase, and has helped the latter on occasion.
- Schoolgirl Lesbians: Kase and Yamada, eventually. And while the story is very light-hearted, it's a bit more realistic than most—Yamada ultimately ends up having to come out to her friend about her and Kase's relationship (though she had guessed), and there were rumours in the school that Kase is a lesbian even before Yamada came along.
- Shrinking Violet: She's not as bad as some, but Yamada isn't too good at talking to strangers and hates big, noisy crowds.
- Single-Target Sexuality: Both Yamada and Kase are completely devoted to each other. In chapter 20 Kase reveals that she's never dated anyone before Yamada, even declaring that she'll never fall in love with anyone but Yamada. It gets to the point that each of them becomes a Clingy Jealous Girl whenever they think someone else is putting the moves on the other.
- That Came Out Wrong: After they start dating, Yamada admits she's never gone out with anyone before and doesn't really know about certain things that couples are supposed to do together. She seems to be talking about dates and bentou and things. Kase is clearly thinking about... something else.
- Later, when Kase gets flustered over the idea of going on a date with Yamada while on a school trip, she mentions that it'll be the first time they spend the night together. When Yamada gets a shocked look, Kase rushes to change the subject.
- They Do: Kase and Yamada have their first time in the last chapter of the original series.
- Through Her Stomach: After they start dating, Yamada tries to make Kase a bentou, but keeps being stymied by Kase leaving class early or being too busy talking to someone else.
- Tomboy and Girly Girl: Kase and Yamada.
- Twice Shy: Though neither girl is all that good at hiding their feelings from the other, it takes a full year for them to get together because they're both too nervous to take the final step.
- Unresolved Sexual Tension: In spades before Yamada and Kase get together. Even something like Yamada putting her arm along Kase's to show how tanned she is has them both blushing and awkward.
- Valentine's Day Chapter: The bonus chapter Chocolate and Kase-san.
- Violently Protective Girlfriend: Kase. Anytime someone else so much as comes close to flirting or acting perverted towards Yamada, expect Kase to appear from nowhere and aggressively scare them off. She'll even leap from the second floor of a building to do so.
- W.A.F.F.: The manga's main purpose.
- Wholesome Crossdresser: Kase herself◊ dresses up in a suit in chapter 7 of Yamada and Kase-san after finding out that Yamada is planning on attending a mixer, causing Yamada to turn red.
- You Are Better Than You Think You Are: Kase regularly expresses that she thinks Yamada is amazing in her own right. Time will tell when Yamada seriously takes it to heart, but as a result of the encouragement, Yamada has decided to aim for a college in Tokyo rather than staying in their town in order to be with Kase.
- Yuri Genre