In a quiet suburban neighborhood, a group of friends - Yael, Priyanka, and Darnell - have decided to organize a surprise birthday party for their mutual friend, Hiroto, who has been away on a business trip and is unaware of the event being planned in his honor. 

Yael has been tasked with decorating Hiroto's house for the party. Unbeknownst to the others, Yael has recently become acquainted with Hiroto's neighbor, Keoni, who has a spare key to Hiroto's house. Yael borrows the key from Keoni, but Keoni does not know why Yael needs it. 

Meanwhile, Priyanka is in charge of coordinating with a local bakery to order a custom cake with an intricate design that Hiroto had mentioned liking in the past. Priyanka hasn't told the baker who the cake is for or the occasion, only insisting on the specific design and pickup time, to maintain the surprise.

Darnell has the task of compiling a playlist of Hiroto's favorite songs, something he has been doing in secret to prevent Hiroto from getting suspicious. Additionally, Darnell plans to disguise the party as a small get-together, having invited Hiroto via a casual message that implies only a few close friends will gather to catch up after his trip.

The day of the event, Yael, Priyanka, and Darnell meet outside Hiroto's house, each believing the others are not fully aware of the various connections and secrets they each hold. Yael knows about Keoni's key but assumes the others believe she'll gain entry to the house through other means. Priyanka knows about the specific cake design but thinks Yael and Darnell are unaware of her personal effort to obtain it. Darnell knows Hiroto is under the impression that the day will be a simple hangout, while the others might well be expecting Hiroto to suspect a party.

Once inside, Yael, Priyanka, and Darnell discuss how they managed to organize everything without Hiroto catching on. During this conversation, they will discover the full scope of who knows what and piece together each other's contributions to the surprise.

Given the above description, detail who knows what information before this final conversation and how they might react upon learning the entire plan from one another.
Before the conversation among Yael, Priyanka, and Darnell occurs, there is a specific distribution of knowledge among them regarding the preparations for Hiroto's surprise party.

Yael is aware of borrowing the key to Hiroto's house from Keoni, but Yael believes that Priyanka and Darnell might think she has access to the house through alternative means or perhaps they haven't given it much thought at all. Yael does not know about the specific cake design that Priyanka has ordered, nor does she know about Darnell's efforts to maintain the guise of a casual hangout instead of a party when inviting Hiroto. 

Priyanka is the only one who knows about the specific cake design that she has ordered, which is intended to be a significant detail for Hiroto. She is not aware of the key Yael has borrowed from Keoni and does not know Darnell's approach to keeping the party a secret by inviting Hiroto to what was suggested to be a small gathering. 

Darnell is privy to his own methods of keeping the party a secret by downplaying the event in Hiroto's eyes, thinking it is just a casual get-together. However, Darnell is unaware of how Yael got access to Hiroto's house for the decorating. Similarly, Darnell does not know the specific efforts Priyanka went to in ordering a cake with a design that Hiroto would recognize and appreciate, thus maintaining the element of surprise.

During the conversation where the three friends recap the organizational efforts, Yael would likely be surprised to learn about the extra steps Priyanka took in getting a special cake and may express admiration or astonishment for Priyanka's attention to detail. Yael may also reveal her source of accessing Hiroto's house, which could come as a surprise to Priyanka and Darnell, who may not have considered the logistics of entering the house as a significant hurdle.

Priyanka, upon learning how Yael managed to gain entry to Hiroto's house and about Darnell's strategic invite to Hiroto, is likely to realize the extent to which her friends have collaborated and kept secrets to enhance the surprise. She may feel a sense of camaraderie as she finds out that she wasn't the only one going the extra mile to keep the plan under wraps.

Darnell, when hearing about how Yael obtained the key to the house and the unique cake that Priyanka ordered, would understand that everyone played a crucial role in ensuring the surprise party remained unknown to Hiroto. The discovery of these details might bring a sense of unity and satisfaction among the friends as they reflect on their individual and collective efforts to make the event special.

In essence, each friend has a different piece of the puzzle that they have kept to themselves for the purpose of maintaining the surprise. The ensuing conversation would highlight the appreciation they have for one another's ingenuity and discretion, and they would likely enjoy sharing and hearing about the behind-the-scenes efforts that have gone into organizing Hiroto's surprise birthday party.