they did kiss but it isn't really shounen-ai,I recommend you to watch the anime since the episode kaworu appears in is way more shounen-ai-like than in the manga.Also don't expect a happy end lol
Yeah, it's Kaworu and Shinji who kiss (I'm pretty sure it's Shinji's first kiss). And about the shounen ai, I guess it's up to interpretation? Kaworu doesn't show up until the last chapter of volume 7, so it's a while before they meet. I felt that Kaworu liked Shinji romantically because of volume 10, and it's not until volume 11 that Shinji admits he was attracted to Kaworu, despite Shinji thinking that boys shouldn't like boys and telling himself that he didn't want anymore friends.
The anime does have more moments between Kaworu and Shinji that could be interpreted as shounen ai, but I thought the episode was quite rushed. The manga also has moments that can be seen as shounen ai too though. Whichever you choose though, like Kaworu said, but there's not a happy ending for them, and the series itself is very sad.
Hey! Is this shounen-ai at all? Apparently the two main guys kiss in this? Is that true? (≧∀≦)