Sig is a main character in the series Upotte!!. She is a Swiss SG 550 assault rifle. Her grades are top notch and she's an honor student, but a bit out of it at times. She sports exceptional firing accuracy at mid-to-long-range and able to survive in freezing temperature (similar to real SG 550), and doesn't like to lose.
- She appears to have lesbian feelings for Funco and gets jealous when others get close to her, like when Sako stole her first kiss, she was shocked that time.
- Funco is the only person who can make her shy and timid.