只因

Meme origin: Cai Xukun's 2018 self-produced song 《只因你太美》 (Just Because You're Too Pretty) contained the line 只因 (zhǐyīn), which sounds like 鸡 (jī, chicken). This birthed the whole 鸡你太美 / 坤坤 meme ecosystem. Now 只因 in online chat almost always signals a reference to Cai Xukun rather than the literal conjunction.

grammar

In literal usage, 只因 = 只是因为 = 'just because'. It introduces a reason clause: 只因…所以… (just because... therefore...).