The story starts with a young boy in critical condition at a hospital and needs a blood transfusion ASAP, but he has a rare blood type that the hospital doesn't have in stock. Luckily, a young girl volunteers to be a blood donor as she has the same type of blood as him.
We fast-forward to the present as we are introduced to Haruka Kuze, who is trying to get contact information from his neighbour, Maruna Rinjou, for someone. He is convinced that such task is impossible and lists practical reasons as to why, only for her to tell him to become a gecko or a skink. He counters her with facts and logic relating to gecko and skinks, but she ignores that as she get light-headed due to low blood pressure. Haruka offers to escort Maruna to the school nurse, but she refuses as she clearly hates his guts. The problem for Haruka is that he is indebted to her as he was the young boy and she was the young girl in the beginning, but she has rejected all attempts to pay off that debt.
Later Haruka spots Maruna alone in a classroom and when she sneezes, a bottle of water begins to float uncontrollably. Maruna spots him and drags him back to her house to explain everything, whilst holding an axe. She explains that she comes from a family of witches and the source of a witch's powers comes from natural energies, such as the moon (which is the source of Maruna's powers). Haruka correctly states she can't control this power and after an attempt to prove him wrong fails, Maruna enlists Haruka to help her find way to do this by 3am that evening as that is when practical exam for the local academy for witches is and she intends to enrol at that school because if she doesn't, her powers wil disappear when she is 16. The reason for getting him to help is that he's very analytical, so should be able to work out where she is going wrong and what the best solution is and there will be solution, as all a witch needs is heart (according to her grandma).
They start by retreading old ground by getting things to float by her sneezing, but the results are the same as before. The next method is to eat super-spicy curry, but that too fails. Maruna's final idea is to take a hot bath (don't worry, Haruka outside the bathroom not peeking) and during this time of calmness, Haruka asks what will happen if she fails the exam as he wants to able to repay that debt he owes her. Maruna tells him that a: she won't fail the exam, b: the blood transfusion was done out of moral obligation so he owes her nothing, and c: she still hates him. He asks why she hates him, which triggers no verbal response from Maruna, but instead triggers a memory where she went to visit him to feed him apples slices only to find him being fed apple slices by a group of doting nurses. Realising she can longer focus, Maruna decides to get of the bath but feels light-headed, so passes out only to wake up naked in Haruka's arms - appropriate reaction occurs.
Maruna heads to the test site alone as a: they won't permit boys on academy grounds, and b: she can't look him in the face after he saw her naked. Haruka heads to bed feeling useless, but perks his spirits up by remembering how useless Maruna must've felt during her earlier attempts that he saw to get her powers to work and still getting up to continue. He refocuses on the advice Maruna's grandma had given her and finally reaches a conclusion and dashes off to find Maruna to put his theory to the test - he hasn't got time to explain it to the audience. Meanwhile, Maruna is struggling to get an apple to float and after 3 attempts is about to be marked down as a failure for the practical exam, when Haruka bursts in, dressed as a girl. Haruka identifies himself to Maruna, explains he is dressed like this to get inside, then grabs her hand. Haruka is asked to leave, but he explains that he and Maruna combine to form 1 witch and he hugs her which causes not only the apple to float, but everything and everyone inside the exam hall to float as well. On the way back, Maruna asks what activates her power as she hasn't clearly worked it out, so Haruka explains her powers comes from having a higher blood pressure, so by stressing her out (who wouldn't be stressed out when hugged by someone they hate) he could raise her blood pressure to activate her powers. Maruna is also weak to physical contact (according to Haruka) and a naked hug would have been ideal, but stripping down in the exam hall wasn't feasible. Haruka gets clobbered for probably justified reasons.
Maruna gets accepted as well as Haruka, which he anticipated, so now she has a minion for the next 3 years and he can finally pay off that debt that he owes her.

Maruna is eager not to be late so scolds him for being slow and making his breasts too big (they’re bigger than hers). Haruka argues that his ‘breast’ size is perfectly average and their argument is interrupted by a rolling glass ball which they pick up. The owner of the glass ball runs over and retrieves the glass ball from them, before apologises for disturbing them before her cat, Nana-chan, knocks the ball out of her grasp and she has to chase after it again. The opening ceremony begins with a normal speech by the academy’s headmistress before the new student that had the 2nd highest score from the entrance exam, Saki Hanamiya, who replaces the highest scorer who couldn’t be there for reasons.
They head to their first class where they meet the girl from their commute, who introduces herself as Miyu Suzunari. Miyu stares at Haruka and comments about his aura, which makes him wary of her. Saki introduces herself to Haruka and Maruna as she was impressed by their practical exam performance and although Maruna doesn’t recognise her, Haruka does but only as 2nd place on the entrance exam rankings. Saki retorts that together they are one witch, individually they are useless. Maruna wishes to fight back but Haruka stops her as Saki is right (also starting a fight is a good way to bring attention). The teacher arrives and explains the lesson: they are to get into groups of 3 and 2 members are to read the other member through a crystal ball, also the harder you try to hide a secret, the easier it becomes for the crystal ball to spot it. The various groups of 3 begin to read one another through their crystal balls, which reveals embarrassing secrets. The group of Haruka, Maruna, and Miyu are slow to get going and fail to complete the task required, so will need to do it again in next lesson tomorrow.
That evening, the 3 begin to work out how to complete the task and Haruka assumes that magic must used, so reminds Maruna that she has a flat chest. She denies this, but her blood pressure is raised enough that the crystal ball begins to float before flying into the pair. Miyu shows them how to properly use a crystal ball as you don’t look into the crystal ball, rather you look through it as if it were a lens to look at someone. Haruka then asks why Miyu held back her talents, as she was clearly capable of doing it, she reveals that she isn’t ok with finding out people’s secrets and revealing them. Her answer explains why Haruka was confused by the lesson as the task was clearly a form of bonding, but it did nothing but drive people apart. Haruka knows what must be done to complete the task as intended and asks Miyu to properly perform the reading tomorrow as she doesn’t need to hold back with him and Maruna - they’re all friends now.
The next day and Haruka and Miyu (actually just Miyu, Haruka has no magic) read inside Maruna and it reveals her inner secret to be her early morning dance ritual. Haruka sees it as reflection of the amount of effort she is willing to put in for just herself. Maruna is embarrassed that Haruka now knows about her dancing, but he then quietly reveals he already knew about it, had been watching her dancing for a long time and he thinks it’s cute, which raises her embarrassment and her blood pressure enough to get a reading on Miyu. The crystal ball reveals Miyu rubbing Nana-chan’s belly against her face, which Haruka interprets as her showing a great affection and care towards living creatures. It’s now Haruka’s turn to be read and her secrets is that she has pads in her bra (4 per breast to be exact) but in Miyu eyes, it is ok to have small breasts. With every group now successfully looked at each other via a crystal ball, the teacher reveals that the interpretation our protagonists had was the correct one, much to the confusion and shock of Saki. After class, Miyu states that she finds Haruka to be mysterious and she wants to find out more about her, while Haruka doesn’t want Maruna to stop her dancing ritual as it gives him 80% of the fuel necessary for his life and she agrees not to, mostly because of what he said to her during the reading.

Today, they're taking physical measurements of the students, so everyone has gathered in a hall and are in their P.E kits (don't worry, Haruka changed in his dorm). Maruna id fired up to do well on the assessments, but achieves the lowest score of anyone on all of the tests, despite exhausting herself in the process. Her blood pressure is high enough that she can use her magic, but she is too tired to properly use it (no control) and her pulse is pounding differently compared to previous times. Their conversation is interrupted by the reactions of those watching as one of their fellow students scores of 50 int the vertical jump test. It's Haruka's go next and he scores just over 70 which puts him right in the spotlight. Hikaru Hibiki, the student who briefly held the record on the vertical jump test, comes over to feel Haruka over. She does this to feel his muscles, but Maruna gets in her way. She introduces herself and notices that Maruna looks tired, so massages her shoulders. The massage is effective and because Hikaru resonates with electricity and has been giving massages to her grandpa since she was young, so has been training her power enough that she has complete control over it.
Haruka performs worse on the other tests to stand out less, but it doesn't dull Hikaru's curiosity as she wonders what is beneath his trousers. She assumes it to be muscly legs that Haruka is embarrassed about, but he knows that when he's weighed he will be heavier due to the more muscle he has (cause he's a guy) and Hikaru will want a proper feel. He asks Maruna to get him to float a bit when he's being weighed, so he will weigh less which will make the statement that he is girl more believable. Maruna is unsure she can control her powers enough to fulfil his request, but agrees anyway. Haruka is less confident, but tells Maruna that he believes in her, whilst grabbing her hand before bringing her face close to his and telling her to only look and focus on him. This all causes Maruna to blush and to believe there to a hidden meaning to his words, although, luckily, the plan goes off without a hitch.
Hikaru concludes that she must have under-performed in the vertical jump test, but Haruka doesn't believe it should be of great concern as doesn't change who she is as a person. Maruna keeps her distance towards Haruka and doesn't speak to him for the rest of the day as the words he said to her before the weigh-in weigh heavily on her mind and gets her blood pumping.

Maruna is doing her dance outside, while Haruka observes and talks to a black cat about how much he owes her and how always wants to help her no matter the cost.
Today's lesson is about learning how to fly a broom, which should be easy for witches who resonate with the moon like Maruna. Haruka has prepared for all situations that may occur today (more tightly fastened wig, shorts under his skirt, last will and testament, etc) except for one (don't ask, he never tells). Maruna attempts to fly, but needs Haruka to generate enough magic to fly, so just skids across the ground. Haruka suggests she needs to be a bit more prepared like Miyu(who is wearing elbow- and knee-pads), whose trying to fly by resonating with her broom's maker and its previous owners. Meanwhile, Hikaru is using her electricity magic to get the broom to fly using electromagnetism, but has as much control as Maruna does with floating objects. Saki shows off how beginners are supposed to fly, but all that people remember about her is that she came 2nd place in the entrance exam so she still loses. We learn more about 1st place witch, who resonates with the moon, which inspires Maruna to start moving on up both figuratively and literally. Haruka asks how Maruna wishes to held, which causes her to blush and she does even further, when Hikaru and Miyu tease them about them kissing whilst in flight as that happens in a famous romantic movie in the witching world. All that blushing raises Maruna's blood pressure enough that she and Haruka quickly ascend high into the sky. The two marvel at the view they have from wap up high, but the mood is disrupted when Haruka informs Maruna that he can't hold back any longer as he is about to be sick thanks to motion-sickness. He had prepared some medicine to counter that, but someone drank it and that someone is Maruna. Haruka loses consciousness and falls off the broom, so Maruna chases after him. She catches him, but can't fly back up and tries to wake Haruka up, resorting to trying to kiss him to raise her blood pressure, however dithers enough that she runs out of time. They are saved by another witch, who recommends that Haruka has his bra removed, which Maruna does, but the witch disappears before she can thank him.
Haruka comes around and presumes that witch that Maruna met is the witch who finished 1st place, but she can't confirm it. He also has this weird feeling after finding out that she removed his bra and concludes it must a form of stress and considers using on Maruna, which she does not like and goes to bed angry at him and herself for nearly kissing him. Haruka goes to bed, while it is revealed the cat he was talking to in the beginning was the same witch that saved him and Maruna and has seen him remove his wig and probably out himself as a guy.
There are 2 bonus comics in this volume. The first one is about Haruka pitching to Maruna different ways to stress her out, while the other is about how Haruka should behave to help maintain the illusion that he is a girl and how much training he really needs.