Shinseiki Evangelion Koutetsu no Girlfriend

A shy female character, Mana Kirishima, starts at Shinji Ikari's school and immediately admits to finding him cute. Gradually, a relationship unfolds and they end up going on a date. It turns out, however, that she is one of three test pilots for the TRIDENT units, a new competitor to the Evangelions, similar to Jet Alone; thus the name Girlfriend of Steel.

[Edited from Wikipedia]