To write an extension properly, one must capture characters and tone (and sometimes theme--see above). If the characters are too unlike their originals, one might as well write one's own story. If the tone is too different . . . why choose this story to pay tribute to in the first place?
Here is one of my attempts (in summary):
Only the Ring Finger Knows Continuation
The series ends with Wataru and Kazuki planning to move in together . . . though not yet.
My continuation goes like this:
They do move in together during Wataru's junior year in college but that particular arrangement doesn't last. I am as pro-romance as any devoted yaoi fan but I have a fundamental uncertainty about the lasting nature of relationships formed in high school. They can last. But so very, very often they don't. Wataru and Kazuki's relationship will--but they need to get some separated years behind them first.
I find it believable that although Wataru and Kazuki would want the relationship to last, they would find it currently untenable due partly to outside forces (college, career choices, family pressure) and partly to personality. Wataru would be uneasy about their relationship preventing Kazuki from joining/rising in his brother's firm. Wataru would also want to stand on his own two feet. After all, Kazuki's tendency to try to manage their relationship single-handedly wouldn't go away overnight.
Wataru ends up moving to the United States (people going to and working/studying in the United States is a thematic thread within the series). When he and Kazuki part, they decide that it's a real breakup (neither of them makes any promises) but they also both acknowledge that they hope that things will work out in the long run.
Because the series needs some drama and soap opera, this is when Masanobu (prior interested party, whose family lives in the U.S.) shows up. He wants to try again to "win" Wataru.
Wataru has always hoped that one day, he and Masanobu could become "just friends." Unfortunately, that is clearly not what Masanobu is after, and Wataru has a fundamental sense of fair play. It is one thing for him to start dating someone entirely new. It's another for him to start dating Kazuki's rival (with whom he was never particularly interested that way anyway). To start doing it after the breakup would give the impression that Masanobu and Wataru were simply biding their time; they always planned to get together eventually.
When Wataru voices his objections, Masanobu instantly backpedals and claims--as he has many times before--that he wants to be Wataru's friend; after all, Wataru has never lived in America before and Masanobu has; Masanobu can help him out. However, by this point, Wataru has matured enough to understand how (non-deliberately) manipulative Masanobu can be. He also knows Kazuki well-enough to realize that should Kazuki learn that Wataru and Masanobu were going out, even as friends, he would make the exact deduction that Wataru wishes people not to make.
It isn't that Wataru is afraid of Kazuki; rather, he has learned that thoughtlessness about how things "look" can lead to people getting hurt.
There's a strong streak of Edwardianism in Japanese culture, as the manga and novels make clear.
Masanobu goes away but in some corner of his mind, he still thinks that (1) Wataru and Kazuki are over; (2) if he, Masanobu, doesn't have a chance, that's because Wataru won't end up with anyone from his old life.
|In the series, everybody has cell|
|phones--still, I like the rotary phone.|
Wataru and Kazuki stay in semi-touch through email and texting (ah, technology). Eventually, Kazuki reaches the point (approximately three years after parting with Wataru) where he is able to go out on his own. He comes over to the United States, where the friend of a friend of a friend sets him up in an interview at a reputable Japanese firm with International offices in Seattle, Washington. He either gets the job or wins the project, which leads to other projects.
In the meantime, he visits Wataru and they semi-restart their relationship. (At this point, they know each other so well that starting over from scratch is unnecessary.) They date and eventually, Kazuki moves into Wataru's apartment in a complex in Oakland (where there's a pool--it's not an important detail; it's just . . . I see a pool! it is important that the neighbors know and like the couple).
And . . . that would be the end . . . except yaoi plots require a pay-off--or at least, a complication!
Masanobu shows up when Kazuki is out of town and Wataru is on his way to work. Masanobu, without being actually physically violent, causes Wataru to fall and hit his head. The way I picture it: Masanobu is in one of his persistent moods because he doesn't understand how Wataru can go back to Kazuki: doesn't Wataru know what's best for him; if he and Kazuki didn't work out before, how could Wataru possibly think they could work out again, etc. etc. etc.
At the back of all this is thwarted love but Masanobu himself may not be completely aware of that emotion--his state of mind manifests itself as "concern." It ultimately comes down to pride (see above).
|Asaka Masanobu: Supposedly|
|mild-mannered, he can act rashly,|
|surprising others and himself|
Masanobu, on the other hand, while appreciating Wataru's empathy, defines it from an entirely subjective viewpoint. He likes to receive Wataru's sympathy and understanding. He fails to take the next step, to credit Wataru with having a fairly hard-headed and insightful understanding of other people and situations. Masanobu's thinking goes something like, Wataru is so gentle and kind when he extends sympathy to me; he is too naive to keep people from taking advantage of him; I must intercede.
Masanobu perceives himself, first and always, as the right person (champion) to "rescue" Wataru. As discussed in the series, Masanobu's longest relationship, with girlfriend Yuina, fell apart because he wanted to be the pamperer, protector, perfect boyfriend all the time. Being the recipient of so much "care" stressed Yuina out, especially since she could never return the favor: Masanobu never accepted being pampered, protected, or simply supported in return. He never stopped wearing the honor-student-face that Kazuki dropped with Wataru from the beginning.
At the end of the novels, although Masanobu has supposedly gained from loving Wataru, he still doesn't appear to have grasped that Wataru would never be satisfied in such an unequal relationship whether or not Kazuki existed. After all, Wataru is the one that chews out Kazuki for trying to rent an apartment without his input and for not telling him, Wataru, when he, Kazuki, was in an accident in New York. Wataru doesn't want to be taken care of--or rather, he does, so long as he can reciprocate.
So Masanobu has gained experience but not discernment. No one is going to "win" the argument between him and Wataru since they approach the issue of dating/relationships from such differing perspectives. In high school, Wataru wanted Masanobu and he to be the type of friends where one person could share his concerns ("I'm not sure this relationship will work, ya know"). Masanobu continually refused that role. He would say he was Wataru's friend, then decide that circumstances justified a closer relationship until Wataru finally had to sever their acquaintance completely. Masanobu doesn't get to show up now and play "best friend."
Masanobu doesn't understand Wataru's resistance. For Masanobu, everything he does depends on his intentions in the present. He doesn't have Kazuki's objectivity, so he cannot recognize his protectiveness as a form of bullying. Unlike Kazuki, he cannot be "called out" on his behavior. Masanobu is thinking, Right now, I'm willing to be a good friend; why can't Wataru see that?
Realizing the argument is going nowhere, Wataru attempts to leave--he isn't going to invite Masanobu in without Kazuki there and he has to go to work--and in the scuffle, he ends up getting hurt.
|Kazuki Shohei with his daughter Takako|
In the end, Shohei Kazuki--who has a Spike-like personality and a semi-antagonist/semi-supportive attitude towards Wataru and Kazuki's relationship--comes over and fixes everything. Masanobu apologizes and leaves; he'll be punished back in Japan through demotion and apologies to family members, a course of action with strong social ramifications in Japanese culture. No one is going to bring charges.
And Wataru and Kazuki remain a couple with stronger (though still tempered) support from Shohei. Wataru and Kazuki's personalities as established in the manga and novels are such that they are quite good at the emotionally resilient aspect of relationships. As Gottman points out, it isn't whether or not the couple is good at talking but whether they have the resources and techniques to ride out the bad stuff.
In the far off future, I postulate the following events (using all first names): Masanobu eventually finds someone else--but he's a guy who likes to live in angst, so it probably won't last; Masa'aki, his brother, and Karin, Wataru's sister, stay in touch--eventually Masa'aki contacts Wataru directly and they remain friends; Kawamura, Wataru's friend from high school, keeps in touch.
Even further in the future: about three years after they get back together, Yuichi (Kazuki) and Wataru end up adopting the out-of-wedlock daughter of Takako, who has proven as much of a handful as her father did in his youth. (Actually, I'm not sure they would/could legally adopt the great-niece; she remains within the family-line of Shohei Kazuki. However, the baby is born in the United States. In accordance with jus soli, she has dual citizenship until she is 22.) Wataru proves a natural father when it comes to discipline and to having fun. Yuichi is the person who helps with the studying.
And naturally, Wataru and Yuichi continue to wear their rings--refashioned and inscribed by Karin based on the old design. 💙