She does not seem to take her job very seriously, greeting any situation with a light-hearted laugh. She generally allows her partner Mr. 5 do any necessary talking. Being a Baroque Works officer agent, she is quite confident in her abilities. Her chosen method of dealing with Usopp--crushing him slowly and painfully by increasing her weight--shows her preference for unnecessary cruelty. She also dislikes being ignored, especially when she is attacking.
Abilities and PowersShe has the power of the Kilo Kilo no Mi (キロキロの実 Kiro Kiro no Mi), which allows her change her mass to anything between 1 and 10,000 kilograms (changed to pounds in the 4Kids dub). She uses this power to crush her opponents, or to make her light enough to glide through the air using her umbrella.
She is partnered with Mr. 5 so she can ride the force of his explosions into the air.
Present StoryShe, along with Mr. 5, find out about the Straw Hat Pirates during the Whiskey Peak arc and fights them along side Mr. 3 and Miss Goldenweek during the Little Garden arc where she is swiftly defeated by both Nami and Vivi. 
She, along with Mr. 5 and Miss Goldenweek, have appeared in a chapter cover mini-story where the three fly from Little Garden to visit their fellow Baroque Works agents in prison but wind up on an island resort swarming with marines. The three later try to disguise themselves but are unsuccessful and are spotted by Hina. While Mr. 5 and Miss Goldenweek escape, Miss Valentine is captured and is about to be executed by the Marines. Luckily, Mr. 2 shows up (disguised as Mr. 3 and pretends to have surrendered) and challenges Hina to a rematch allowing Mr. 5 and Miss Goldenweek time to rescue Miss Valentine and escape. They manage to break many agents out of prison except for Crocodile who refused to go with them and Mr. 1 who stayed with Crocodile. They then started a new Spiders Cafe.
Major Battles* Miss Valentine Vs. Vivi
* Miss Valentine and Mr. 5 Vs. Zoro Vs. Luffy
* Miss Valentine Vs. Usopp