Man, the Naruto and Sasuke buildup is honestly wild when you really break it down. It's this constant push-pull, life-or-death closeness where actual fighting feels more intimate than anything else. They're screaming each other's names, trying to kill each other, and then suddenly they're inches apart, panting, and you're like... oh.
A classic trick is the 'almost' moment right after a major fight. Think about the Final Valley clashes. They're both exhausted, bloodied, and just staring, all that anger draining away leaving something raw. The writer stalls the dialogue, focuses on a flicker in the eyes, a shaky hand, the way Sasuke looks away then back. The tension isn't about the kiss itself but what's unsaid in that stillness.
Another method is parallel isolation. Separating them for chapters, having Naruto think about Sasuke during a quiet campfire scene while Sasuke, somewhere dark and alone, remembers their childhood. It builds this magnetic pull. By the time they're in the same space again, any proximity crackles. The actual kiss is just the release valve for all that narrative pressure.