```ruby
module Kuroko2
  class Engine < ::Rails::Engine
    isolate_namespace Kuroko2
  end
end
```

Add requiring gems to before_configuration
user
```ruby
module Kuroko2
  class Engine < ::Rails::Engine
    isolate_namespace Kuroko2

    config.before_configuration do
      require 'kaminari'
      require 'chrono'
    end
  end
end
```
assistant