Hey, guys this a new chapter I came up with and it's probably not great but I like some criticism for it, anyway here's how Nao reacts to Zero with Hiroki (by the way Zero Is a girl this time, gender bend one's, I accidentally messed up my wording caused by the auto-correction so please re-read the previous chapter if you haven't also I re-edit it too.)

-nao was Hiroki's girlfriend. She loved him the way he was and loved how he was, but when that foreign transfer student found out his name was Kokujin.
-at first, she doesn't like him until when he puts Hiroki in an injured state kokujin gives her pleasure that Hiroki never gave her, and then after Hiroki has recovered from the hospital, she still has intense sex with Kokujin behind Hiroki's back, and her perspective of him in her eyes, he's a weakling, not strong like kokujin, and so she initiated a plan.
She suggested that both Kanako and the leader, mother, and sister of Hiroki add to the kokujin harem that he has taken.
Although she didn't plan on Ayumu being in his harem (kokujin), she also suggested a video of them having sex in his room (hirokis room), and then a month later the Hiroki discovered what his family and friends were doing and she enjoyed his cries.
And then by that time, she broke up with him, and she still did it in his room with Kokujin just for hirokis suffering.
But then, years later, nao has been feeling empty this whole time, when she has sex with the transfer student all she feels when he is done and satisfied with himself was pain after the aftermath, and when he does it rough with her, she feels used up more then she feels loved, and that's when she remembers hiroki of how he treat her like a princess and a maiden, but she shrugged it of and just thought in her head that maybe she can have a lovely with Kokujin like how hiroki takes her on dates, kokujin did go on a date with nao, but it was for a different reason, he takes her in different restaurants just to have sex in the bathrooms, and when she ask to go on a movie he just ask for a headjob from her In theater, nao doesn't feel any love from him, she just feels used up and not in a loving way, everything he ask her to have sex with her, she just look at him in a frustrated look and also annoyed, and it's been a month since she haven't seen hiroki, and just remembering hiroki made her missed him, she missed his love, his cheerful smile, his energetic attitude, and his gentleness, so when she went to school where hiroki goes to, and when she sees him she was about to come to him and to talk him in taking her back, but when she was about to talk to him, she heard him talking to someone, curious as she is, she listened to his conversation with some he is talking to him, when when she sees who he is too, she was supprise to see that he was talking to a girl that she has never seen or heard of before, and then she has a look of shock, hiroki kissed the girl and then the girl indulge in the kiss in a loving way that a couple would kiss, and then she realized that hiroki was confessing with that girl, and the girls said yes, so nao decided to come out of her hiding spot, she confront him and ask him who is this girl he just kissed, and he told her that this is zero, his long time best friend and now his girlfriend, so nao tried to persuade hiroki to take her back and that she will be better but he just decline her and just walked away with his new girlfriend (zero) while holding hands, and then nao clench her hands in a anger manner, and this is the start of her Jealousy that will soon grew fast as the days passed, and her obsession with Hiroki will rise faster.

The next chapter will be about Kanako and Keade's regrets.