|Affiliation||The Washimine Group|
|Manga||Chapter 22: Fujiyama Gangsta Paradise Part 1|
|Anime||Episode 19: Fujiyama Gangsta Paradise|
|Japanese Anime Voice||Houko Kuwashima|
|English Anime Voice||Lalainia Lindbjerg|
Yukio Washimine (鷲峰 雪緒 Washimine Yukio) is a high school senior and the only daughter of Ryuzo Washimine who was the former kumicho (boss) of the yakuza organization "Washimine-gumi" (The Washimine Group).
As the only surviving direct relation of the former boss of the Washimine Group, Yukio is the only one with a viable claim to the leadership of the Group. She reluctantly takes up the leadership when Hotel Moscow steps up their efforts to claim a part of the Japanese criminal underworld. Because of this, she inevitably falls into the world of the Yakuza, eventually being devoured by the tragic darkness she so feared.
Because of this, not only did Yukio prove to be foolish, reckless, and naive, she also became inconsiderate of other people's feelings other than her own, as when she snapped at Rock for his "freedom", never once allowing Rock to explain or even considering that it hadn't exactly been his choice to join the world of crime to begin with; when she refused to cease the fight against Hotel Moscow despite knowing that they were outmatched and outwitted; when she decided to use Rock as bait for Hotel Moscow, despite knowing the outcome and ignoring the fact that Rock was a human being and once a friend to her; and when she carelessly barraged about her status as the leader of the Washimine Group in the final episode, unaware that she was inadvertingly leading Ginji Matsuzaki to his own doom until it was too late. Only by that time did Yukio seem to finally return to her senses, including of her realizing her selfish actions towards others. Whether this was Rock's intention is unknown.
While no romance is directly shown, it is alluded that she is deeply in love with her lifelong bodyguard Ginji. As the arc nears its end it becomes increasingly clear that Yukio had hoped to run away with him to Roanapur to stake a claim in that world of crime.
Before she became the head of the Washimine Group, Yukio was a student hungry for knowledge. She loved to read in her spare time, particularly books concerning philosophy. She applied these philosophies to her life as is shown during her lunch meeting with Rock when she quotes Jean-Paul Sartre.
Thoughtful, intelligent and talented, the misfortune of being the only heir to the Washimine group proved too much for Yukio to live by. After Ginji is killed by Revy, Yukio couldn't stand the thought of a life without him, and possibly the guilt of leading him to his death, before she stabs herself in the throat with his sword as she dies next to him on the dock.
- The name Yukio means "snow" (雪) (yuki) and "thread" (緒) (o).
- Yukio's surname Washimine means "eagle" (鷲) (washi) and "peak, ridge" (峰) (mine).