The Type 31 Engineering Protective Jumpsuit (EPJ) was designed for the Star Army of Yamatai in YE 30 for use the following year and was discontinued in YE 36.

The Star Army set the following goals:

• The suit should be a one-piece garment that is easy to put on and can be worn with OR without a duty uniform beneath.
• The suit should also include protective gloves and optional overboots
• The suit should be compatible with the Star Army Helmet, Type 30.
• The suit has to be form-fitting, so it fits in maintenance tunnels and won't get caught on things.
• The suit should be fireproof, in case of on-board fires.
• The suit has to provide radiation protection, in case of engine leaks and such.
• The suit should provide excellent protection against electrical shocks
• Knees and elbows of the suit should have extra padding for crawling in maintenance tunnels.
• The suit should be available in red (engineering/technicians) and light blue-gray (general purpose)