One night, Kokoro finds her older sister doing research with books on love, and she asks if Kotonoha has kissed Makoto. When Kotonoha doesn’t deny it, Kokoro realizes that she has. At school the next day, Makoto tells Sekai about how fun he thought it’d be to get a girlfriend, and when he doesn’t say anything after she tries to get him to mention some fun times, she scolds him for being half-hearted about it all. During lunchtime, the conversation between her friends about how far Nanami’s gotten in her relationship with an older boy causes Sekai to look upwards towards the rooftop. At that moment, Makoto is kissing Kotonoha, but when he gropes her breast, she pulls herself away. He reminds her that she had said that she’d try her best, so she tells him that she is, however her heart’s still not ready yet. Kotonoha then excuses herself saying that she has things to do, and that night, she calls Sekai to talk about it. Since Kotonoha is feeling a little guilty, Sekai blames Makoto for rushing too quickly, however Sekai also asks her about not wanting to do ecchi things with Makoto in the future, so Kotonoha mentions men who ride horses and describes an idealized situation of being together in a mountain lodge in Europe.
Kotonoha later finds out that her father got two tickets to the water park, so she decides to invite Makoto. However, her chance to ask him on the train the next day is ruined when a bump causes her to fall towards him and him to accidentally grope her breast. Kotonoha instinctively turns away from him because of this, but when she faces him to apologize, he stares out the window and says that it serves him right. His distant attitude prevents her from inviting him, and this is all seen by Hikari who tells Sekai about it later. During lunch, Sekai asks Makoto about how his relationship with Kotonoha is going and mentions being worried about him being impatient with ecchi things. When he yells at her, she drags him out into the hallway and has him tell her about what’s going on. Since it boils down to Makoto wanting to do ecchi things to Kotonoha, Sekai says that wanting such things for someone you love isn’t wrong, but the way he’s doing it is. She decides to help him out with some special training, and during class, Makoto writes her a note asking what that means. Sekai replies that she’s going to teach him about girls’ feelings, and after class, she takes him to the park.
After finding a relatively quiet place, Sekai tells Makoto about the ideal situations Kotonoha had said it would be okay to do ecchi things, and she brought him here because of how much Kotonoha seems to like nature. As for their actual training, she offers to teach him how to kiss, but before they can, they get discovered by a bunch of younger kids. Their next destination is a karaoke box, but Makoto points out that they don’t any privacy here either because of the surveillance camera. With no other choice, Sekai and Makoto return to school and head to the rooftop where it’s just the two of them. Sekai first has Makoto link his fingers with hers and then has him touch her hair before getting him to gently embrace her. When she wants him to whisper into her ear that he likes her, Makoto uses her name instead of Kotonoha’s, so she corrects him. However, Sekai isn’t quite sure about him touching her chest next because she doesn’t have experience with something like this, so she suggests he gently caress her breasts. While he’s touching them, she accuses him of thinking that they’re smaller than Kotonoha’s, and he admits that he did.
After a little more caressing, Makoto suddenly tells Sekai that he wants her, and he soon pushes her down onto the bench. Sekai struggles at first, but she eventually stops and lets him continue because this is special training. However, right as Makoto takes off her ribbon and starts unbuttoning her shirt, his cell phone beeps with a text message from Kotonoha asking for forgiveness for what happened this morning. In the end, Sekai and Makoto go home, and when they part ways, Makoto asks Sekai about continuing their special training. Sekai, however, refuses him and says that he should do it with Kotonoha. By chance, Makoto then runs into Kotonoha, and she asks him if he read his mail. He hadn’t, so Kotonoha apologizes for this morning and invites him to the pool. Still nearby, Sekai watches the two with a sad look in her eyes.
ED4: 「記憶の海」 (Kioku no Umi) by yozuca*
That entire scene between Makoto and Sekai was pretty intense in the sexual tension department, approaching what I’d call a softcore tease. He actually got a lot further with her than I thought he would in his “special training,” and the two of them didn’t get caught either – I kept expecting Kotonoha to discover them up there any minute, but it never happened. In terms of long term drama potential, it’s probably better that she doesn’t find out about any type of relationship between Makoto and Sekai until her own relationship with him is further along, in which case such a revelation would become devastating, to say the least.
However you look at it though, Makoto cheated on Kotonoha with Sekai. I could be convinced that it might have started out as Sekai genuinely wanting to help Makoto (even though the phrase “special training” raised all sorts of warning flags in my head when she first mentioned it), but it definitely ended as something more than that. Still, I didn’t find myself blaming Sekai until she stopped struggling after Makoto pushed her onto the bench. She technically gave him consent to do a lot of foreplay-type things before that, but that seemed like the point where she was willing to go all the way. In short, I think Sekai is just as responsible for all this as Makoto is (if not more), but since I’m not a huge Kotonoha fan, I don’t feel particularly bad for her either. Right now, I’m just curious to see what happens from here because it’s clear that Sekai has a ton of feelings for Makoto, and he might even prefer her to Kotonoha.