Apparently fishermen put an octopus in a plastic bag with salt, and spin it for 45 minutes in a washing machine. Think of emulating that as you rub that beast very, very well.

When it's no longer slimy, rinse well in water.

I heard that the octopus becomes tender if you bash with a daikon radish so I tried it out, but there wasn't a lot of difference between an un-bashed tentacle. In any case, the octopus did becomes somewhat tender.

A sushi chef told me that if you boil octopus with bancha green tea, it adds color, the skin doesn't peel off easily, and that the texture of the flesh is improved, so I tried out the tip.

The key to making the legs roll up nicely is to submerge in the boiling water tentacle first, take out, putting back in, and repeating several times.

When the tentacles have rolled up cutely, put the whole thing in the boiling water.

You can adjust the boiling time, but if you boil it for too long it will become tough. I boiled a 1.2 kg octopus for about 5 minutes.

Take it out when it's boiled, place in a sieve and cool under running water.

Cool down quickly in ice water, until it's no longer warm when you touch it.

Chop off the tentacles one by one.

As long as you rub it very well with salt until it's no longer slimy, I think it's hard to screw up.

Enjoy as sashimi and carpaccio, and use the rest in simmered dishes and enjoy!