On SRCL-9520 he's credited as キタムラタケシ, and on SRCL-11242 he's credited as 北村岳士.
The evidence that these are the same person comes from the fact that both songs are co-composed with Yo-ichi Tanoue, an employee of PAPA X, a company which Takeshi Kitamura is the director of:
http://www.papa-x.com/company.html