trains can be cheaper if you are smart about it
hotels arent as bad when you have someone else with you can share a twin room. most larger hotels offer 30% off if you stay longer than 3 days, works out to about 70 each. capsule hotels are about 20 each, 15if student. business hotels 40-45 per night, 35-40 if student.
10grand is too much unless you are eating at expensive restaurants, drinking in roppongi every night and getting hookers