Hi Okabe,
Like MedRamy, I also applied to Tokodai (Tokyo Tech) for Chemical Engineering. I was going to apply to Mechanical Engineering, but Kubouchi-sensei in ChemE does research closer to my interests so I switched. However, I have talked with Mizutani-sensei from MechE a lot and he is very nice, very smart. What area of aerospace do you want to study? Materials/mechanics, dynamics/controls, or flight/fluids?