Following text has been copied from the .flow wiki's page Girl in the Yellow Dress.Yellow Dress Girl (or the "Girl in the Yellow Dress", "Mysterous Girl" or the "Girl") is a mysterious girl introduced in ver. 0.18, located in an a hidden area of the Apartments and at the end of the Vomitgirl Area in ver. 0.19.
To find her, you must eat cake in the Sugar Hole 10 times (requiring about 3,000 yen) and each visit must be a separate flow session, quitting the game during this will erase this progress. During the 11th visit, talk to the two maids at the Sugar Hole and go back to the Apartments where one will find a now accessible stairway (originally, it was blocked by a traffic cone) .The stairway leads to a room where an apparition of her and Sabitsuki will be seen having tea before mysteriously vanishing. This event is nicknamed the "Sugar Float Days" event and to exit this event, one will have to use the Arms effect or wake up.To find her in the Vomitgirl area, you must eat cake 5 times (for 1,500 yen) and this also requires a separate flow session each. Once you've eaten cake five times, visit Sweet Sugar hotel and interact with the maid (which has a hole where her face is) there. There is a 1 in 5 chance of triggering the event, so one may have to interact with her more times before the hole spreads across the screen and teleports you to the Vomitgirl Area.
The Girl will be waiting atop a giant female statue, beyond Sweet Sugar, staring into a black void while melancholic music, implying a sad or tragic event. Neither Rust nor Sabitsuki can interact with her.
- Even though she has a full set of walking sprites, she's not animated, doesn't react to any effects, nor can she trigger events when encountered in-game
- There are dead girls with similar appearances to her, laying around Sweet Sugar.
- It can be proposed that lol meant for her character for have some sort of importance, considering that the "Sugar Floats Days" event appears to be a flashback and the effort needed to see her, along with that she has a full set of walking sprites
- It's suggested that the Girl has some sort of importance to Sabitsuki's character but speculation ranges from a potentially girlfriend, a sister, a friend, or Sabitsuki's mother. The most most consistent being that she's either Sabitsuki's mother or sister.
- Her standing at the edge of a statue in the Vomitgirl area is near reminiscent of her standing at the edge of a cliff or on a balcony.
- Similarly, one theory tying into the above, suggests she committed suicide.
- Because it takes much effort to trigger the events she's seen in, the theory would be, in connection with the above, that there was something tragic and Sabitsuki tried to forget about her
- Since Sweet Sugar has allusions to prostitution (probably in the form of "compensated dating") and the Vomitgirl Area's rather overt sexual imagery, it's inferred that the Girl was either a prostitute or that she was involved in prostitution somehow.