Kashiwagi Yuki (柏木ゆき?) was the first and only female customer of Club Suizokukan. She went to the club because she found out that her fiancée, Ueno Hiroshi, was frequenting it using borrowed money. After meeting Same, she felt defeated, but was given help by the Suizokukan girls by letting her become one of them for a day to get close to Hiroshi, under the genji name Anago (アナゴ eel?).
Yuki was engaged and is to marry her fiancée, Stylist Ueno Hiroshi. During the duration of the Majisuka Jyogakuen girls' Cabaret Club project, Ueno Hiroshi became one of their frequent customers, which was noticed by Yuki after she noticed him drinking more often, has an unfamiliar perfume scent on his clothes, and has Miyawaki Sakura's "Same" calling card in one of it's pockets. She also found out that he was borrowing money from a loan shark, saying that it was for their marriage, but was actually using it on Club Suizokukan.
When she went to Club Suizokukan to investigate, she saw the different personalities of the girls that scared her. After she saw the Suizokukan girls chase after customers who ran away without paying, Kurage found her, in which she was mistaken for an applicant, and later as another Majijo Graduate, but Yuki quickly denied it. She was invited in as a regular customer, and was treated as a special guest, since she is the first female visitor of Suizokukan aside from the applicants and guest cabaret girls. Before Saionji could finish his welcoming remarks, Yuki quickly bursted out Same's name, which Saionji inquired if she was requesting for Same to accompany her. Meeting Same, she was asked why she picked her, and she tried to dodge the question by answering that she finds her cute when she was looking at their homepage. Looking at Same thoroughly, she felt defeated and decided to just go home, but was stopped by Same. Afterwards, she began telling Same all about Ueno Hiroshi being her fiancée and how she actually found out about their club. Same reluctantly told her that it is their policy not to talk about their customers to others, but assured Yuki that even if Hiroshi did come to their place, they only treat him as one of their customers and nothing more. Confused if she should disclose more or not, she began drinking the whiskey that Same prepared earlier in one gulp. She began telling Same everything after around a couple more drinks. Looking pale, Same was concerned if she was ok. Feeling woozy, Same tried to assist her to the toilet, but they were surprised to see Hiroshi enter the club and hid behind a cubicle near Karei. Feeling a bit angry that he came to the club when he said that he would just be overtime late at work, she snatched Tsujimoto Tsuyoshi's fork and proceeded to walk towards the room Hiroshi reserved. Seeing Hiroshi with another girl aside from Same, she dropped the fork as she saw how happy Hiroshi was. Kurage then took her to the girls' side room to give her something to soothe her, with 5 other Suizokukan girls other than Same attending her. After a few words from the Suizokukan girls, she decided to try being one of them so that she could get close enough to Hiroshi to confront him.
Several days later, she was introduced to Hiroshi as one of Same's helpers. Given the genji name "Anago", she shocked him by her presence. She then proceeded to ask for more sake. When he attempted to walk out of the room by saying that he needs to go to the toilet, Anago stopped him, daring him to get drunk that night and talk to her about everything.
- Some fans speculate that Anago could be Black, but since her character's identity is only named as "Kashiwagi" (柏木?) in the Cabasuka Gakuen Webpage (Nezumi and Kojiharu are both identified as both Utsubo and Konbu, respectively), and unless another reliable source comes out, it is possible that they are not the same person. Add to the fact that Anago already denied that she went to Majisuka Jyogakuen when Kurage spotted her.
- Kurage had mistaken her for another Majijo Graduate, but she denied that she went to Majisuka Jyogakuen.
- Her last name is revealed on the Cabasuka Gakuen website, while her first name was mentioned by a surprised Hiroshi upon recognizing his fiancée as Anago.
- Anago (穴子?) is a salt-water eel, a contrast to her Co-NGT48 member Kitahara Rie's Unagi (鰻?) which is a fresh-water eel.