Just ONE astronaut?
Am I reading this right? Does JAXA intend to send just one astronaut to land on the Moon, do EVA/sampling/photography etc.? No crewmates to tend a mothershp in lunar orbit (will it be EOR/LOR or direct-ascent?), and serve as copilot for the lander? Or, does JAXA plan on a one-man lunar orbit/flyby mission as a kind of "technology demonstrator"? This article doesn't mention that.
Towards the end of the Mercury program, if I remember right, plans for a one-man lunar flyby based on a modified capsule were kicked around and quickly dropped. At least Gemini could carry two and, in the context of the heavily-studied Lunar Gemini proposals, one man could tend the Gemini in lunar orbit while his crewmate flew a bare-bones lander down to the surface. Also, the USSR's original plans for Soyuz lunar missions called for a crew of two working in a similar fashion as the proposed Lunar Gemini missions.
Just one guy, though? I don't think they've really thought this through enough.