Um, it's the most common on that suits 90% of common jap bikes. Use a dab of grease on the face to crank end to prevent damage.
This will explain
https://www.motoxparts.co.nz/p/flywh...rsal-nac-tools
27x1mm
I like the motion-pro one, simple robust, can give it a shock with a hammer.
Like go hold flywheel with this to undo. Have to position carefully so don't snag pulsar coil. Available from supercheap etc for not much.
https://www.google.com/search?client...d7j8NovOpOvkM: