Johkasou　systems　have　emerged　as　quintessential　examples　of　decentralized　wastewater　treatment　technologies　due　to　their　compact　design,　easy　operation,　and　robust　resistance　to　mechanical　impact　attributes　that　are　particularly　effective　in　mitigating　and　treating　rural　domestic　wastewater.　Although　the　efficiency　of　the　Johkasou　process　in　removing　nitrogen　and　phosphorus　has　been　well-documented,　a　comprehensive　synthesis　of　the　underlying　mechanisms　and　influencing　factors　is　still　elusive.　This　review　seeks　to　elucidate　these　aspects　by　detailing　the　biogeochemical　pathways　involved　in　nitrogen　and　phosphorus　removal,　characterizing　the　key　microbial　consortia,　and　addressing　the　potential　accumulation　of　nitrous　oxide　(N2O).　Furthermore,　the　review　critically　examines　the　impact　of　various　media　used　in　Johkasou　systems　on　nutrient　removal　efficacy,　with　a　particular　emphasis　on　nitrogen.　It　also　proposes　a　range　of　practical　adjustments　to　design　parameters,　including　dissolved　oxygen　(DO),　pH,　temperature,　and　hydraulic　retention　time　(HRT),　to　enhance　process　performance.　Finally,　the　practical　implementation　of　Johkasou　systems　and　their　integration　with　ancillary　processes　in　actual　domestic　sewage　treatment　scenarios　are　synthesized,　providing　a　theoretical　foundation　for　advancing　Johkasou　methodologies　in　rural　areas.