Not sure if this is already common with Takeda but..
When you do EX Kunai and hold it.. you'll typically get a throw if you try to use 3. So for example.. you'll throw EX Kunai and you'll do 3,3,4. If you do 3,3,4 while holding 1, a grab will come out. But, for some reason, there are times where the normal will actually come out while you're holding 3.
Here's another example: EX Kunai (hold) > d3 > Release Kunai > f1,2 2+4 xx db1 (close). This is a jailing blockstring that the opponent is forced to eat if you land the d3.
You can also do things like: EX Kunai (Hold) > f3 > release Kunai > stuff
EX Kunai (Hold) > f4 > release Kunai > stuff
The f3 and f4 after the EX Kunai is tricky if you're looking for a jailing blockstring (That into f1,2, 2+4)
F3 has a lot of blockstun as well.. and is typically safe. F4 is a high but it's +2 on block and it hits on crouched blocking opponents.