When Hishigi is on the verge of Driven to Suicide after implanting the Devil Eyes, Fubuki refuses to kill him and then hauls him to his feet by the front of his shirt, saying that Hishigi is not allowed to die until Fubuki says he can.
Fubuki seems to be trying to Break His Heart to Save Him on several occasions, approaching aggression in his statements that if Hishigi isn't comfortable with what they're doing, he can leave. Hishigi's response is always some form of You Are Worth Hell.
Before Muramasa's departure from the Mibu, he told Hishigi, "take care of Fubuki for me."
Just before stabbing himself in the heart in order to activate the secret technique of the Taishiro, Fubuki tells Hishigi, "You have my thanks for standing by me all these years. I wish you to live until the end."
Hishigi's death scene. He has taken several of Kyo's most powerful attacks in attempts to shield Fubuki. The Devil Eyes have been destroyed, leaving him extremely weak and dying. But when Akari mentions Fubuki, he manages to get to his feet and attempt a Taking You with Me with Kyo. When that doesn't work and his body starts dissolving, he staggers to Fubuki and rips out his own heart, implanting it in Fubuki so that he can continue living after destroying his own. In the original, he says that he will live on with Fubuki. This is the English translation of his Final Speech, given just moments before he dies in Fubuki's arms:
Hishigi: It seems my heart still works... even after losing yours, this should enable you to live on....
Hishigi: A-and when... did I ever need your thanks...? You pompous fool.... I-I have never claimed... to be accompanying you.... Y-you have no crime to feel guilty of.... I chose... my own way. I picked the place I would survive... until death finally found me....
Muramasa: (flashback) Hishigi, look after Fubuki for me.
Hishigi: I'm sorry, Muramasa. I could not keep my promise....
Hishigi: Thank you, Fubuki... I hope you can find the heart... to forgive me... for leaving you all alone....
Yukimura says outright that he loves Kyo at one point. Then again, pretty much everyone loves Kyo.
Akira's crush on Kyo started around the age of ten.
Hishigi once tells Kyo that he has beautiful eyes, while touching his face. Hishigi's not even trying to dispel the rumors. Of course, it's entirely possible and pretty heavily implied that Hishigi actually is gay, and just about everyone flirts with Kyo at some point.
During his fight with Tokito and before he finds out that Samus Is a Girl, Akira says that Tokito has "a sweet face, which hides the wretched coldness of your heart."
Saizo's Bodyguard Crush on Yukimura (even more blatant in the anime than in the manga, which is impressive) is played for laughs on a regular basis.
Yukimura also has some with Shindara, also known as the original Sarutobi Sasuke, who was once his most trusted soldier.
Played for laughs with Akari, who was designated male at birth and is in love with Kyo. Her gender is accepted enough to be another woman even in Kyo's eyes — he has actually promised to marry her if she ever lands a hit on his face. This doesn't stop some of the more clueless characters from flipping out regarding the contents of her undergarments.