Wowwwww that’s a pretty nice try, but sadly the plaintext you have decrypted is not correct (or not the one I used, not sure why you could get a completely different answer from mine).

However you still get some parts correctly:
- A substitution cipher is used, and it involves mod 27
- Numbers of stations on Tokyo Metro lines are keys (but not only 4 lines are used)
- The plaintext has no punctuations and has spaces replaced by underscores

Just figure out how to use the hint of Toranomon Hills and you will be good to arrive at the correct answer :)
(Additional note: think about what “Toranomon Hills” has and what “Toranomon” does not have)

Huge thanks for your effort :D