Thoughts of who Richard will end up with also a bit of spoiler and theory (?).... . Spoil...

Thoughts of who Richard will end up with also a bit of spoiler and theory (?)....
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From the raws of the manga I found, Buckingham will later want Richard to be bare his heir (I think) to the point he chained/abducted Richard to the bed and forced him in women clothing. Ofc Richard is not okay with it and well his and Buckingham desire collide and I think that really strained their relationships. Also the twins get poisoned like just after they found again their brotherly love (not incest way but when they realized that they literally have only themselves... )

I think, Richard's love for Henry will come back while what he felt for Buckingham will weaken. It's a bit daring to say, but I think the infatuation Richard has for Buck is mainly imprinting. Buck was the first person that trully accepted everything that Richard is. Example before they became a thing and Richard starts to ask for Buck's warmth, there was a flashback of young Casterby that instead of telling Richard "You're great as you are" when Richard was being bullied for having odd eyes he instead made him hide what people didn't like of him. The "you're other eye color is odd so let me cut your hair so you can cover it". It's cute that he cared for Richard but ultimately he made Richard feel like he should be ashamed of parts of himself.

Richard fell for Henry who in the end refused his love. When Richard dressed up as a woman when he confessed to Henry, I think he acknowledge he was a woman and that he fell in love=womans love for a man. If Henry didn't hallucinate / affected by Cecil's words and his fear of sex and women, he would have accepted Richard as he present himself to him as his woman self. Henry loved Richard but didnt know he was a woman. So Henry accepted Richard's man side but wasn't ready to accept Richard female side. (plus he still hasnt to dealt with his phobia of women)
Richard then get the misconception that his female love is wrong and just a sin that should be left as it is. Thus he decided to be a man as he buries the love of a woman he had and his woman side, along with Henry's coffin and as he accepted to wed Anne.

Buck accomplished what Casterby/Henry couldn't. Buck didn't told Richard he should hide his body or refused his womanly side. He fell in love with Richard. Genuinely loved Richard and so Richard female side found solance and Richard himself feels comfortable with his female side when he is with Buck. So they both in peace with each other... BUT as we see later Buck is starting to have the need for Richard to be his and not be with other women. Plus add Richard still has feelings for Henry and refused to call Buck with his first name which is the same as Richard first love... So that certainly add insecurity issue to Bucks at the the idea that Richard loved another man. My guess is that their relationship will strain as seen in the raws too, because he wants Richard to be just his woman self. He wants to have a child with Richard and have him wear female clothes... I think this forced desire of Buck will result in Richard interpreting his actions as not respecting her/his wishes, time and doubting her trust(and well if I was Richard I would feel more comfortable and happy if my partner r both love my woman & man side equally).

My theory is that Buck will try to bring down Richard from the King's seat and idk.. Fake Richard's death so he can hide Richard as a lover (lol let's remember that Buck is married). Mainly because if Richard is the king it is harder to kept that position if it comes out that the king is homosexual... And from previous events, people practically will believe anything and will think every king is bad. People always thinks that whoever is in the leader's seat is not doing enough or corrupted... So Buck will try to betray Richard so he can him away from the king seat and have at his side. A bit dramatic but according to irl Richard 3rd he gets betrayed by Buckingham and well so far the author respected the crown succession. (tho author didn't add that Richard had other children other than Edward...)

My guess is that Henry is still ML. Henry will fall in love with Richard all over again but most importantly he learnt to love Richards' female side. At that point he will ask Richard to accept his feeling but it's gonna be difficult for Richard to take back the first love he buried plus add that he loves Buck too but is uncertain after Buck forces him to be a woman..