Ultimate Combat -- Kyoketsu Shoge Confusion

[QuantumWings]

I'm thinking of playing a character with a kyoketsu shoge, how does it work mechanical?

Does it work like a whip (can hit anything within 20ft, doesn't threaten),
a reach weapon (threatens things exactly 10ft away can hit anything within 20ft by throwing blade).

The weapon list says it can do slaying of piecing damage and is a single weapon, while the description says it is a double weapon that can do bludgeoning damage.

Can someone please clarify what this can and can't do?
It is a weapon that is full of ninja flavor, but unless I know how it works I can't use it.

[Illeist]

This.

Also, does using a kyoketsu shoge at a range of 20ft. require you to throw it? By RAW, nothing changes the general mandate that using melee weapons at range means throwing them. So apparently you have to pick up your entire weapon, chain included, and lob it in the general direction of your enemy. It would make a lot of sense for this to work like the rope dart, but, mechanically, it doesn't.