ネタバレ
Netabare
ねたばれ
A mashup of ネタ (neta, 'the content/punchline of a story') and バレる (bareru, 'to be exposed/found out'). It means revealing key plot points or endings of movies, anime, manga, or games to someone who hasn't seen them yet. In Japanese internet culture, spoiler etiquette is taken extremely seriously — 'ネタバレ注意' ('spoiler warning') tags are considered mandatory. There's also 早バレ (hayabare), which refers to leaked manga pages that surface online before the official release date.
Examples
ネタバレしないでね！まだ観てないから
Don't spoil it! I haven't watched it yet.
Stopping a friend who's about to discuss a movie
うっかりネタバレ踏んでショック受けた
I accidentally ran into a spoiler online and I'm devastated.
After stumbling upon plot details on social media
ネタバレ注意って書いてあったのに読んじゃった
It said 'spoiler warning' and I read it anyway.
ネタバレされたけど、それでも面白かった
Someone spoiled it for me, but honestly it was still good.