It's a cute story about a girl that receives a very very good looking robotic boyfriend (and if you haven't figured it out as yet, it's shojo so the rest of the series will follow her dilemmas in love).
Kaji plays someone on the research/development team, he doesn't talk a lot, his job so far is to poke and prod at Mokomichi's firm wonderful robotic body.
I *THINK* his character's name is Tanaka Yujirou?
EDIT: Softsubs here!
(Thanks to wakalaka for pointing this out.)