A Study of Tocilizumab in Chinese Participants With Systemic Juvenile Idiopathic Arthritis (sJIA)

Inclusion Criteria: * Participants meeting International League of Associations for Rheumatology (ILAR) classification for sJIA * Greater than (\>) 6 months of documented persistent sJIA activity prior to screening * Active disease * hsCRP \>4.3 milligrams per liter (mg/L) or 0.43 milligrams per deciliter (mg/dL) * Participant who has recovered from any symptomatic serositis for at least 30 days prior to the screening visit, and requires a dose of CSs at baseline of \</=30 mg/day or \</=0.5 mg/kg/day, whichever is less * Participants meeting one of the following: Participant who is not receiving MTX or discontinued MTX \>/=4 weeks prior to baseline visit; participant who has been taking MTX \>/=12 weeks immediately prior to the baseline visit and on a stable dose of \</=20 mg/m\^2 for \>/=8 weeks prior to the baseline visit, together with either folic acid or folinic acid according to local standard of care * Participant who was never treated with biologics or, if was previously treated with biologics, discontinued etanercept (or Yisaipu, Qiangke, or Anbainuo) \>/=2 weeks, infliximab or adalimumab \>/=8 weeks, anakinra \>/=1 week, or abatacept \>/=12 weeks prior to the baseline visit * Participant who is not currently receiving oral CSs, or is taking oral CSs at a stable dose for \>/=2 weeks prior to the baseline visit at \</=30 mg/day or \</=0.5 mg/kg/day, whichever is less * Participant who is not taking NSAIDs, or taking \</=1 type of NSAID at a stable dose for \>/=2 week…