Rain is a young woman with shoulder length blond hair that has a single red streak on the right side of her face, purple eyes and she wears black sunglasses quite often.
She is usually seen in a sexy black leather biker suit that exposes her cleavage, her shoulders, her backside and her butt, black boots that go up to her calves, a small cross necklace around her neck and her boobs stand out whenever she has sex with Lady J.
Rain is shorter than Lady J as their heights are different:
- Rain is 158 cm in height
- Lady J is 172 cm in height
Rain is shown to be very daring and nonchalant in the overall course of the series. She is almost always seen with Lady J (Rain's partner and lover) as they are usually on the same page, more so in battle and she has a strong relationship with her and they often move in sync as they are Liberator/Extar hybrids, usually fighting together and sometimes partnering up with other inhabitants of the island. She developed the Arm virus early in her life so she was used for her ability and after sometime in her life she has developed a strong desire for freedom in her choices. In the more serious moments of the series, Rain is either in Extar mode being used for her Disarmament Buster by her partner or is playing the role of Liberator with her partner to escape or fight against their foes. She is very observant, just like her partner and when at a disadvantage their partnership shines through all the more when they do all they can to be on the winning side of a battle.
- The name Rain means "Abundant Blessings From Above" in American.
- Rain also derives from the Latin name Regina, which means "queen".
- Rain's surname Hasumi means "lotus flower, water lily" (蓮) (hasu) and "fruit, good result, truth" (実) (mi).
- Rain and Lady J (Rain's partner) are former agents of the Nafrece Intelligence Agency.
- Whilst being a Liberator, Rain is also an Extar or "arm" (known as hybrids).
- She becomes a powerful cross-shaped gun when in extar form.
- Due to her strong abilities and powerful bond, she and Lady J are able to combine into one arm known as their Final Form.
- It is possible both Rain and Lady J are easily able to switch to and from their Liberator and Exter forms without the others aid.