Kusama is a scalable network of specialized blockchains built using Substrate and nearly the same codebase as Polkadot. The network is an experimental development environment for teams who want to move fast and innovate on Kusama, or prepare for deployment on Polkadot.
Kusama is a Substrate-based chain. You can use Polkadot JS app to access your wallet and stake with Polkachu. The staking link and a step-by-step video walk-through is provided below.