Upotte's portrayal of the G3A3 German diesel-age batter rifle. 

Known as "Jiisuri" (a mispronounced interpretation of G3).

Jiisuri is tall, black haired, and usually drawn with brown or greyed eyes. She is moderately busty but wears tight clothing that hides this; a reference to the G3's slim but heavy handgaurd. Unlike most of the other students at her academy, she wears an entirely black and grey uniform except for a large red bow placed on her breast (a reference to the G3's all black finish). She (and her sisters) are also one of the only characters in Upotte to wear pantyhose, a reference to her fairly unique looking plastic stock. 

Jiisuri is normally very calm, somewhat aloof and competitive. The eldest of her sisters, she oversees and "parents" all of them to an extent. These qualities attracted Farru (FN FAL), another battle rifle who is much like Jiisuri in many ways, and the two share a close friendship and are often allied in school competitions. She is also fairly close with M14, another battle rile, and Funnco (FN FNC), an assault rifle and the main character of Upotte.

While Jiisuri is normally fairly calm and mature, she is a bit of a blushing housewife at heart, as revealed though her interactions with teachers at her school and with the manga's readers (Upotte's artist likes to add 4koma style strips at the end of certain chapters, where questions submitted by the readers are answered by the Upotte cast.) Jiisuri in her appearances is open, friendly, somewhat skittish and oddly flirtatious. She even poses for a personal, rather lewd personal photo shot as  part of a popularity poll.

Jiisuri is also one of the most popular Upottes; she won the first "Shounen ace Upotte popularity poll," trumping all the other characters.
g3a3 (upotte!!)