According to Ashitaka
of the Lain mailing list, the Kanji sound for 'Rein' means 'the sound of jewels. 'Iwakura' is the name of a samurai
group serving under Iwakura Tomomi. The Meji emperor sent the samurai to Europe to study European culture in 1872-73. Gn0sis
informs me that Iwakura literally means: 'Stone Warehouse'.
These are the names of Iwakura Lain in Japanese:
Romaji: Iwakura Rein
Thanks to Ashitaka of the Lain mailinglist.