In Network, go to Japan Ministry Of Transit. On the site, you will find a simulator "map". The password is: SINTJ. When using this map, you'll face Imaginary Numbers and SF WZR Pilots, with the best armament available in the game(?), and body hp from 700 to 1200. You can't beat them, BUT from every shot you fire at them, you'll receive atleast 25 exp, and if you hit, even more exp. Kill one, and you get 300exp:s. Also learn Exp X3 from Shangdi1 legs, these you get automatically in Alisa's story.