Keymo opener is a 6-3 opener developed by Keymo, along with winterfrost. It starts with an incomplete kaidan-cutcopy followed by 2 t-spin doubles, and leads to stable 6-3 midgame.

Benefit of keymo opener: It has a good build rate, and for queues where you it can't be built, other very good openers can be used. 2 solid examples are Tki and Mko (Queue -> IJL can be used for both Mko and Tki)

The opener is also known as Divorced gassho, as in gassho, the S and Z minos are hugging, but in this opener, they have separated, and Z piece found a new partner (T piece.)

First bag

The opener has very few dependencies, all you need is O before I. If you can make the LSJ box early, the rest of Bag 1 is buildable. S as first piece, placed vertically all the way to the right, also makes bag 1 buildable (you can softdrop the L).

Second bag

Main route (needs L before O)

DT cannon

This continuation breaks the 6-3 type of stack but is quite rewarding, especially if you follow through with the ST cannon afterwards.

Continue like so for the ST cannon (always buildable with 180). After the TST of the dt cannon, freestyle-fill the ghost tiles to have your ST cannon.

Here is a different way to make the DT cannon

The diagram below shows some ways to make the overhang for the DT cannon

Alternatively, if you get J before O you can always continue the 6-3 stack with a fractal instead of a DT Cannon.

Third bag

This is the ideal third bag. You can either take the top or bottom part of the fractal depending on your piece order. It is possible to always stack this way if you don't mind taking a TSS and skimming sometimes.

Other ways to build the third bag. Either way, the goal is to make the fractal.

In the 3rd and 4th diagrams above, if you need to spin the Z (L before Z), do a standard z-spin, 180, then clockwise rotation.

Fourth bag and later

After the end of keymo opener, (bag 3), you can continue to 6-3 stack and build numerous floating tspins