No.305 (参丸伍號, San maru go gō) was a housekeeper robot created under the Fuyou Project.
No. 305 was the latest Robot Housekeeper model produced by the Fuyou Project specialising in the area of cleaning. She was returned due to her obsession with cleanliness that borders on compulsion, which her owner found it annoying.
She was working as a janitor in the research facility during the event of Fuyou Arc.
Her body was later recycled by Hiraga Gengai for Tama's use, but was subsequently destroyed in a large explosion due to Tama's self-sacrifice to prevent a large-scale destruction to Edo.
No. 305 has long pink hair and green eyes. Identical to Tama's look, No. 305 wears a blue yukata with a white apron, white thigh high socks and a pair of wooden sandals. She also carries a broom as both a cleaning tool for work and as a weapon.
No. 305 appears to have borderline obsessive compulsive disorder, cleaning everything that she deemed as dirty due to a malfunctioning ability. This includes Tama's mole when the latter was still working at the lab.
She was also fiercely loyal to Professor Hayashi, believing that the man's capability of turning the robots into the status of gods.
No. 305 first appeared with Professor Meguro and No. 502 outside the Yorozuya office in an attempt to retrieve the 'Seed' that was planted in Tama's head. They gave chase after realising the trio had escaped with it. No. 305 soon finds them and attacks by smashing her broom on the ground. The blow missed Gintoki and gang and the chase continued.
The gang arrived at an intersection and made a sharp turn, managing to slow No. 305 down. Just then, a truck came up from but was destroyed by the robot without much difficulty. It was later explained that No. 305's main role was to erase all the filth that would threaten the Fuyou Project, often leaving no traces behind. She soon catches up with the gang and demanded for Tama's head to be returned. After exchanging words with Tama regarding the 'Seed', No. 305 then begins fighting the gang.
She was decapitvated by Gintoki in an attempt to ditch her while he and Kagura tried to escape on Sadaharu's back. However, her body managed to hold Sadaharu down to prevent them from doing so. As a last resort, Kagura ordered Sadaharu to do something, who in turn took a dump on the road. The trio then escaped, leaving No. 305 behind to clean up the dump as part of her program as a housekeeper robot.
Her body was later brought to Gengai's by Sadaharu, which the inventor recycled it to store Tama's data in order to assist the Yorozuya against No. 502.