Episode Summary: Just another day at Chiaki’s school, when her friends ask if she has a relation to a boy named Touma. They go investigate to find that he really is a she, but Chiaki is determined to have a brother. Chiaki isn’t satisfied with her prey and turns to leave, but only to be hit from behind by a boy who was pushed by Touma. Chiaki stands up, and demands that Touma say sorry. He, or she, starts to believe that she, or he, really is a boy; Chiaki asks when his birthday is and finds that it is in fall, younger than her, and she stops the conversation by telling him not to ask a girls age. She then tells him that she will raise him right as her brother.
When the school day is over, and also Chiaki’s lessons, they walk out to find that something is still missing; Chiaki switches Touma’s and Makoto’s backpacks(Black is for boys, and pink for girls). Later, Makoto is learning how to cook so that he can impress Haruka in the future, but unfortunately, he has no idea what he is doing. He is attempting to cut an egg with a knife in order to peel it; he is easily shown up by Chiaki, who is boiling the eggs to perfection. She taunts Makoto by telling him that she cooks with Haruka every day, and not just once like him. He points out that he is a Chef’s egg(a beginner) and that his will be filled with tons of feeling; he states that he can take anything, so boil him. Chiaki responds with a quick jab.
When Kana and Haruka come home, they find Chiaki in a odd position with Touma on top of her. The group sits down and talk about the new relationship, and that Touma’s name spelled out is actually winter, rather than fall. Touma states that she is actually a girl, but Kana and Haruka just can’t believe it. With this, Chiaki and Touma start at it again, and Chiaki is easily overpowered; breaking up the squabble, Makoto, in his girl outfit, busts in and shows Haruka a cookbook. Upon seeing Makoto, Touma has to check to make sure of just who it is. Touma finds out that she is indeed Makoto in a girls outfit, and they come to the conclusion that they are both trying to be the other sex.
They return to the table along with an awkward silence, and Touma tries to get everyone to believe that she is a guy. Kana calls over Touma and lifts up her shirt, but only comes to the conclusion that she is just more feminine than Chiaki. With this, Makoto jumps up and says that Touma is a boy, but when Kana wants to prove the feminine traits, he says she is a girl. The next day, Makoto is at the Minami house, and states that he cannot hold the secret of Makochan from Haruka any longer; he tries to state that his manliness cannot be hidden any longer, but he looks more feminine than usual. Interrupting their conversation, Haruka and Chiaki walk in.
Chiaki starts to talk, but is stopped by extremely chapped lips; Haruka puts some lip balm on Chiaki’s lips, then her own. Makoto could try and tell the truth now, but is distracted by the lovely Haruka and her lips. Haruka notices that Makoto’s lips are also chapped, and applies the same lip balm on his, at this, he flushes. Touma is enticed also, and starts to say indirect kiss, but is interrupted by Kana. At this, Makoto comes out and states that he is indeed a male. Haruka seems unaffected by the turn of events, and Haruka, Chiaki, and Touma go to make curry for dinner.
While in the kitchen, they talk about Makoto, and Haruka and Chiaki think that Makoto is really a girl; they think that he is really trying to pull the same stunt that Touma did. Touma turns to the living room, and states that Makoto might not be able to become a male around Haruka. The next day, Touma states that Makoto’s confession was misunderstood, and comes up with the idea to tell Haruka and Chiaki separately. So Makoto busts into Chiaki’s classroom and states that he is male, but his attempt at truth is again misunderstood. Makoto returns to Chiaki, and gets on his knees and states that he is a male, but again, Chiaki doesn’t understand because he is wearing boys clothes. Back at the Minami residence, Kana, Makoto in boy clothes, and Touma are talking about reverting to Makoto boy-form.
Makoto busts out his Makochan transformation kit, but before turning into Makochan, Haruka and Chiaki come home. Makoto still dressed as a boy, hides under the kotatsu and is surrounded by skirts and legs. The girls turn on the tv to a magic show, and Kana is excited and kicks Makoto under the table by accident. Kana is playing with Makoto now, and he is clinging to Touma’s lap. Kana decides that she has played enough, and has Touma try a magic trick, make someone appear after shoving clothes down a kokatsu. She stuffs the clothes under the table, and Makoto is changing with the new clothes; with the hairpiece on, she pulls Makochan out and Haruka is astounded. Thus ending Episode 10 “Boy X Girl”.