Complex sentence: Ho Ho Lun's first Japanese event was in 2012 in which he participated in the Tenkaichi Jr Tournament of Pro Wrestling Zero 1, although being eliminated in the first round by Irish wrestler Sean Guinness.
Split into simpler sentences: Ho Ho Lun's first match at a Japanese wrestling event occurred in 2012, when he participated in the Pro Wrestling Zero1 (ZERO1) Tenkaichi Jr Tournament. Lun was eliminated in the first round by Irish wrestler Sean Guinness.