I'm guessing much of the funding comes from the Japanese government. They funded the Chikyu project which resulted in a deep drilling robot they plan to reuse.
The Chikyu is a (very large) riser drilling ship, not a robot. Other than that, dead on. The Chikyu was more or less built to drill the "mohole", and the Japenese government has been fairly set on it. However, it would almost definitely be a part of IODP (the Integrated Ocean Drilling Program), so the US would play a role in funding it, as well.
