The Sengoku Basara anime takes this trope and runs with it:
Yukimura: My heart is burning. Such presence. Such fighting spirit. Such... strength.
Sasuke: Er, please don't tell me he lit your soul on fire.
- It's even more obvious (and lampshaded by Sasuke) in a later episode when Yukimura and Masamune reflect on how badly they want to fight each other.
Yukimura: The one I really want to fight is Date Masamune, the One-Eyed Dragon!
Sasuke: You really fell for each other...
- In the second season they fanboy each other in what can only be described as daydreams. In the last episode Masamune even seems to sense when Yukimura goes down.
- Even Judge End, the newest season, does not let up at all, with Masamune having dreams about fighting Yukimura and declaring that he is the only one who can set him on fire. Oh, and Yukimura is surrounded by sparkles.
- You know you've got serious Foe Yay in your anime/game series when even the T-Shirts come off as slashy.
- Masamune and Yukimura sit on the fence between Foe Yay and simple Ho Yay, because while they are enemies who will one day probably fight to the death, they actually like each other, enjoy fighting each other, and outside the battlefield they get along pretty well.