Yasu is a vice admiral in the Marines who is quite young considering her military rank. While she may look innocent and cute, on the battlefield she's far more powerful then she appears to be. At a young age, she managed to get a hold of her devil fruit, the Awa Awa no Mi, and has since then attained great mastery of it. She serves under the Orange Dragon, an Admiral who's sense of justice mirrors her own.
Yasu's entire personality can be summed up by the word, chilled. She often doesn't take the enthusiastic approach that her fellow marines seem to have, instead taking on a more diplomatic and relaxed approach. She would prefer to talk things over a drink or settle matters over a game than to turn everything into a fight. In her leisure time, she would prefer to relax instead of train, usually practicing her guitar or thinking about life.
Not much is known about Yasu's life before the marines and she often says it isn't very important either. She's rarely seen in battle so very few if any individuals outside of the marines know about her could name her by face. Despite this, she holds the rank of Vice Admiral, meaning she must at least know several Rokushiki techniques.
She's been seen spending time with Elroy Griffith before his transfer, so it's suspected that the two are a couple. Regardless, there's always a chance she may visit him from time to time.