Set 75 years after its predecessor, Steel Angel Kurumi 2 sees a fresh series of mis-adventures for the beloved Steel Angels. After accidentally stumbling upon Kurumi Mk. II, high school student Nako Kagura becomes Kurumi's master through a chance kiss. However, Nako's friendship with Uruka is put to the test when Uruka becomes envious and resorts to using her father's army of top-secret mecha to destroy Kurumi and win Nako's affection. Things take a turn for the worse when Saki Mk. II awakens due to Uruka's actions, and Karinka Mk. II enters the fray to steal Nako away from Kurumi, creating utter chaos.