Masaki Kajishima (Tenchi Muyo/ Dual! Parallel Trouble Adventure) is making another spinoff entitled Isekai no Seikishi Monogatari. The story is set in an alternate world called Geminar, where countries have fought endless wars with replicas of humanoid Seikishi weapons that they found in ancient ruins. 15-year-old Kenshi Masaki, the half-brother of Tenchi Muyo! protagonist Tenchi Masaki, is summoned from another world to Geminar. Here is a trailer that only show the characters so far:
http://seikishi.com/special/trailer2/index.html
The chacrters shown are the main character Kenshi Masaki, Princess Rashara Aasu XXVIII, the royal guard pilot Kyaia Furan, the weaponry instructor Mezaia Furan, the student mechanic Wauanrii Shume, Princess Aura Shurifon, Doll, Yukine, and Maria. No word when it'll premier.