one's backside / the back, the rear (both spatially and temporally)

an accident resulting in a personal injury or death; often a traffic injury

a traffic accident

mnemonics, the art or practice of improving one’s memory

a mnemonic, a system to aid remembering

(colloquial) current boyfriend

everything

(slang) Alternative form of 彼氏 (kareshi, “boyfriend”)

everyone, one and all

a back gate / (figuratively) the anus, as a homophone for 肛門 and in contrast to 前門 (zenmon, “front gate”, figurative for vagina)